Thermochromic liquid crystal temperature indicator

ABSTRACT

A new and useful thermochromic liquid crystal Indicator is disclosed that provides an indication of the temperature of the Object to which the Indicator is attached, and is an improvement over the existing art for at least the fact that the impact of ambient air circulating around the Indicator and circulating the Object is reduced by several means, such as i) the use of a novel cap or housing to isolate the liquid crystal Structure from ambient air and from touching or ii) using a novel liquid crystal formulation that reduces the reaction time of the thermochromic liquid crystal contained in the Indicator to changing temperatures conveyed by the ambient air. The new and useful liquid crystal Indicator can also employ either a template or a colored filter as a mask that narrows the colors and narrows the range of temperatures indicated by the Indicator. Further, the new and useful Indicator can also employ a new manner in which to indicate that a predetermined temperature or predetermined temperature range has been reached in that it eliminates the confusion arising from the use of multiple temperature indicating panels that were present in the prior art devices.

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/120,207, filed Feb. 24, 2015, entitled“THERMOCHROMIC LIQUID CRYSTAL TEMPERATURE INDICATOR”; and U.S.Nonprovisional Patent Application Ser. No. 14/875,517, filed Oct. 5,2015, entitled “THERMOCHROMIC LIQUID CRYSTAL TEMPERATURE INDICATOR”.These applications are hereby incorporated by reference in theirentirety.

GOVERNMENT RIGHTS

Certain aspects or embodiments of the disclosed invention may have beenmade with Government support under SBIR grant Award No. IIP-1431014awarded by the National Science Foundation. The Government has certainrights in those certain aspects or embodiments of the disclosedinvention.

BACKGROUND OF THE INVENTION Field of The Invention

Embodiments of the invention relate to a temperature “Indicator”. Moreparticularly, the present inventions and various embodiments disclosedherein pertain to, for example, an embodiment of a novel Indicatorcomprised of a novel indicator strip containing thermochromic liquidcrystal; and the thermochromic liquid crystal in the indicator stripindicates when a predetermined temperature has been reached by changingto a certain or predetermined color (the “novel Indicator strip” or“novel Indicator structure”). Another embodiment of the presentinventions pertain to a novel indicator having a novel indicator housingused in conjunction with either a prior art Indicator Strip or inconjunction with the novel Indicator Strip/Structure. Embodimentscontaining one of or both a novel Indicator strip/structure and a novelIndicator housing will hereinafter be referred to as a novel Indicator.

Discussion of The Related Art

The present inventions relate to temperature monitoring of perishable,or temperature sensitive products, or objects for which temperature isimportant to its function (collectively “temperature sensitive product”or “Product”) in which the useful life of that Product is dependent upona function of its cumulative exposure to a particular stimulus, such astemperature, over a period of time through the use of Indicators.Although such Indicators may be used in multiple scenarios, fromforehead thermometers to fish tank thermometers, for purposes ofillustration only, the detailed disclosure in this application willfocus on the use the Indicators in conjunction with Objects that should,for example, be used to ensure the safe shipment and/or storage of thetemperature sensitive product (the “Object”). And more particularly,this application will use as an example of the Object a panel filledwith Phase Change Material (“PCM”), wherein the Indicator is used inconjunction with PCM-filled panels (i.e., the indicator is used tomonitor these Objects and indicate when they reach a predeterminedtemperature or temperature range) so as to ensure that the Product beingshipped is packed for shipment within its proper temperature range.

By way of example only, many types of temperature sensitive products,such as pharmaceuticals (and more specifically vaccines), must bemaintained within a temperature safe zone of between 2° C. and 8° C.from the time of manufacture until they are used. If such Objects areexposed to temperatures that are either below or above their respectivesafe zone, the Products can spoil and/or become inert.

Therefore, it is important to insulate such Products by maintaining themin a temperature-constant environment when they are being shipped orstored. To aid in shipping the Products in a temperature constantenvironment that protects that Product from harmful temperatureexcursions, an entire industry has arisen around the manufacture and useof a “cooler system.” These cooler systems employ a box (typicallymanufactured using corrugated and/or insulated walls), wherein the boxcontains removable hollow panels that aid in the insulation of the box.These hollow panels are typically made of highly durable plastic, andare filled with an insulating material. Preferably, the insulatingmaterial used is a Phase Change Material (or “PCM”), which as its nameimplies, changes phases as it moves through various temperature ranges.These phases include a solid when the PCM is frozen, ½ frozen and ½liquid when melting, and is a liquid when all the PCM warms past itsmelt point.

A cooler system is typically a box made up of any number of PCM-filledpanels. For example, the cooler system can include six PCM-filled panelsthat are arranged in the shape of a cube. The PCM has several differentoperating temperatures, but for the sake of illustration herein, thePCM-filled panels are pre-conditioned to a temperature of −20° C. priorto their use. Once pre-conditioned, the PCM-filled panel is removed fromthe freezer unit and is placed in a warmer environment so that it canthaw to its “Packing Temperature Range” or “PTR”. The PackingTemperature Range is the temperature range at which the cooler system isassembled, and is also the temperature range at which the Product beingshipped can be safely inserted into the cooler system. For example, whena cooler system or box is packed with six PCM-filled panels, it canmaintain the 2° C. and 8° C. temperature (by way of example only, thetemperature necessary for the shipment of vaccines) for possibly as longas ninety six hours. To have a cooler system that employs PCM-filledpanels maintain that 2° C. to 8° C. temperature inside the cooler systemfor the length of time it takes to transport the Product, themanufacturers of the PCM-filled panels recommend that the cooler systembe assembled, and the temperature sensitive product be placed insideassembled cooler system, when the temperature of the PCM-filled panelsis between, by way of example only, 2° C. and 5° C. Thus, the PackingTemperature Range for assembling the six PCM-filled panels into thecooler system, and for inserting the exemplary vaccine Product into thecooler system for shipment, is between 2° C. and 5° C.

As discussed above, the use of PCM as a part of the cooler systemenables the cooler system to better maintain a constant temperatureenvironment inside the assembled cooler system for an extended period oftime, thereby better protecting the Product being shipped inside theassembled cooler system from exposure to harmful temperatures. There area couple of challenges, however, associated with the use of PCM-filledpanels in the cooler system as it pertains to determining when thePCM-filled panels have reached their Packing Temperature Range. By wayof example only, one such problem is that the user who is shipping thetemperature sensitive product (such as vaccine) typically employs anelectronic infra-red temperature sensing device (the “IR gun”) to scanthe surface of the PCM-filled panel so as to obtain the surfacetemperature of the PCM-filled panel.

Not surprisingly, there are several problems associated with using an IRgun to determine the surface temperature of the PCM-filled panels.First, the surface temperature is impacted by the temperature of theambient air touching the PCM-filled panel, and therefore the IR gun moreclosely reports the temperature of the room where the PCM-filled panelis thawing in conjunction with the temperature of the PCM, rather thanreporting the temperature of the core of the PCM-filled panel. Second,the PCM inside a PCM-filled panel will begin melting at the surface ofthe PCM that touches the interior side of the PCM-filled panel, and thenthe melting of the PCM will move toward the interior of the PCM-filledpanel. The problem this melting feature creates as it pertains to thepacking of the cooler system, is that the very thin layer of melted PCMthat touches the interior of the PCM-filled panel might be within thetargeted Packing Temperature Range of between 2° C. and 5° C., but themajority of the PCM inside the PCM-filled panel can still be at a muchcolder temperature (such as anywhere between −20° C. to 0° C.).Essentially, the IR gun is unable to measure the core temperature of thePCM-filled panel.

This pertains to another problem associated with the use of PCM-filledpanels, specifically that the PCM-filled panel may not be completelyfilled with PCM. In such a situation, if the PCM-filled panel is frozenhorizontally with Side A up, the “dead air” or “head space” will becollected at the top of Side A in the interior of the PCM-filled panel.Similarly, if the PCM-filled panel is defrosted with Side A up, the airin the dead space will reach the warmer targeted packing temperature(for example, 3° C.) faster than the rest of the PCM in the PCM-filledpanel. Consequently, when the person packing the cooler system uses theIR gun to determine the temperature of the PCM-filled panel, that IR gunwill mistakenly determine that the PCM-filled panel is within thePacking Temperature Range, when it is in fact much colder.

Alternatively, if the panel is frozen with Side A up but is thendefrosted with Side A facing down (i.e., with Side B facing up), the PCMwill be touching the interior wall of Side B of the PCM-filled panel.Because this inside wall of Side B will cause the PCM touching it tomelt faster than the PCM at the interior of the PCM-filled panel, whenthe user employs the IR gun to determine the temperature of thePCM-filled panels, she will still reach an inaccurate reading of thetemperature of those PCM-filled panels as described above.

These issues associated with the use of the IR gun to determine the truetemperature of a thawing PCM-filled panel results in the followingproblematic situation: i) if the cooler system is assembled at the pointin time when the surface of the PCM-filled panels is registering between2° C. and 5° C.; ii) but the interior of the PCM-filled panels isactually −4° C.; iii) the assembly of the six PCM-filled panels into acooler system will result in the thermal energy of those PCM-filledpanels super-cooling the interior of the cooler system down to about −4°C. (the “Super Cooling Effect”). The consequence of the Super CoolingEffect is that the temperature sensitive product being shipped insidethe cooler system (such as vaccine) will be exposed to that −4° C.temperature, causing the Product to freeze (and most likely be renderedineffective). Thus, there is a need for an Indicator that can betterdetermine the actual temperature of the PCM-filled panel(s), and moreparticularly can better determine the actual temperature of the interiorof the PCM-filled panel(s), and thereby avoid the problems associatedwith assembling a cooler system containing the six PCM-filled panels atan improper temperature (e.g., prevent the PCM-filled panels fromsuper-freezing (or as explained herein, prevent the problems associatedwith “super-thawing”) the Product being shipped or stored).

A problem with the prior art Indicator strip is that the currentlyavailable thermochromic liquid crystal formulations provide a very quickresponse to the temperature to which the prior art Indicator strip isexposed. Although such a fast-response device may work well whenmonitoring certain Objects in certain situations, in other instancesthis quick response time is actually detrimental. For example, when theprior art Indicator is used to monitor the temperature of PCM-filledpanels, the formulation of the prior art thermochromic liquid crystal istoo sensitive to the influences of ambient temperatures.

More specifically, as shown in FIG. 1A, FIG. 1B and FIG. 1C, the priorart Indicator strips are typically placed on a side of the Object beingmonitored (which in this instance is a PCM-filled panel 100). Becausethe prior art Indicator 120 is typically placed on the same side of theObject 100 that is impacted by the ambient air circulating around theObject 100 (and by default impacting the prior art Indicator 120 strip),and because the temperature of the ambient air is very different fromthe temperature of both the prior art Indicator strip 120 and the Object100, the temperature reading of the prior art Indicator 120 strip isnegatively impacted by that ambient air, because the ambient airnegatively effects the accuracy of the prior art Indicator strip 120.

For example, if a PCM-filled panel 100 that had a prior art Indicatorstrip 120 attached to its top surface 105, was defrosting on a lab tablefrom its pretreatment temperature of −20° C., and the room temperaturewas at 21° C., that panel would slowly warm to its Packing TemperatureRange of 2° C. to 5° C. in about twenty minutes. However, if a fan wasnearby the lab table and was moving air across the PCM-filled panel 100and the prior art Indicator 120, the fan would cause the prior artIndicator strip 120 to indicate a colder temperature than the actualtemperature of the PCM-filled panel 100. This combination of themultiple temperatures (the core temperature of the PCM-filled pane 100,the temperature of the ambient air, and the temperature of the airmoving across the prior art Indicator strip 120, will cause the priorart Indicator strip 120 to display an inaccurate temperature indicationto the user that is monitoring the temperature of the PCM-filled panel100, because the prior art Indicator strip will likely indicate that thetemperature of the Object 100 is colder than it actually is (but theindication could be warmer that it actually is depending on thetemperature of the ambient air). Other instances of ambient temperaturenegatively impacting the operation of the prior art Indicator can arisesimply from a person walking past the thawing PCM-filled panel 100 towhich the Indicator strip 120 is attached; or from a person touching theprior art Indicator strip 120 (and thereby imprinting the person'sthermal signature onto the prior art Indicator strip 120).

All these examples of ambient temperature negatively impacting theoperation of the prior art Indicator all lead to the same result asdescribed above—an inaccurate temperature indication generated by theprior art Indicator, which leads to the user assembling the coolersystem too soon, and super-cooling the temperature sensitive product(such as vaccine) being shipped. Thus, there is a need for an improvedIndicator with a housing that better insulates the Indicator strip fromthe negative ambient influences arising from airflow and physicaltouching.

Another problem with the prior art Indicators is that the operation ofthe device is dependent on the speed at which the thermochromic liquidcrystals contained inside the Indicator “operate”. Specifically,thermochromic liquid crystals operate by changing color in response tochanges in the temperature impacting the thermochromic liquid crystals.This response (i.e., the color change) occurs because the spacingbetween the thermochromic liquid crystal molecules changes thereforechanging the wavelength of the light reflected to the observer.

The problem associated with the operation of the thermochromic liquidcrystal as it pertains to its responsiveness to temperature is that thethermochromic liquid crystals are “too responsive” to the temperaturesto which they are exposed. For example, if a slight breeze is created bya nearby fan, or is created by someone walking past the prior artIndicator, and that breeze is a temperature different than that of theObject to which the prior art Indicator is attached and is monitoringthe temperature of, that breeze results in the prior art Indicatorimproperly indicating a temperature that is different than the one thatshould be indicated (i.e., the temperature of the Object being monitoredby the prior art Indicator).

The responsiveness or speed at which the color of the prior artIndicator strip changes, is directly correlated to the speed at whichthe thermochromic liquid crystals change their orientation in responseto a change in temperature. This change in orientation is simply afunction of the way in which the thermochromic liquid crystals operate.Unfortunately, that quick responsiveness leads to the Indicatorindicating a temperature different from the temperature of the Objectbeing monitored; which could lead to the user assembling the coolersystem at the wrong point in time (and ultimately super-cooling orsuper-thawing the temperature sensitive product being shipped in thecooler system). Thus, there is a need for an Indicator strip containinga thermochromic liquid crystal formulation that includes a componentthat slows down the responsiveness of the thermochromic liquid crystalsreacting to a change in temperature.

Another problem with the prior art Indicators is that the liquid crystalformulations employed in the operation of the prior art Indicator have awide range of operation when compared to its color change. For example,assuming a thermochromic liquid crystal is formulated to begin changingcolor (has a “Red Start”) at 2° C. and complete its color change at 11°C., the following should occur. First, when the thermochromic liquidcrystal contained in the prior art Indicator is below 0° C., the priorart Indicator strip will appear black (assuming the color of the backinglayer facing the user is colored black) because no color is beingreflected off the thermochromic liquid crystal to the user.

Depending on the formulation of the thermochromic liquid crystal insidethe prior art Indicator, as the liquid crystal warms to about 2.0° C.,the liquid crystal reaches its Red Start and will turn a reddish color.Then as the temperature of the thermochromic liquid crystal inside theprior art Indicator strip continues to warm, and approaches about 3.0°C., the thermochromic liquid crystals continue to change their spacingand start to reflect a green color to the user. Thus, the “Color Range”of the red color in this example is about one degree Celsius (i.e., fromabout 2.0° C. to about 3.0° C. but it could reach 3.5° C.). Then as thethermochromic liquid crystals continue to warm and change theirorientation, at about 4.0° C. they start to reflect a blue color to theuser. Thus, the Color Range of the green color in this example is aboutone degree Celsius (i.e., from about 3.0° C. to about 4.0° C., but itstart at 3.5° C. and could reach 4.5° C. or even 5.0° C.). One ofordinary skill in the art will recognize that the combination of theColor Range for the red color plus the Color Range for the green coloris known as the “Color Play” or “Width”. It is also understood by one ofordinary skill in the art that the thermochromic liquid crystalformulation can be formulated so that the Color Range for red color caneither be equal to, or not be equal to, the Color Range of the greencolor.

Similarly, as the thermochromic liquid crystals continue to warm andchange their orientation, at about 7.5° C. they start to reflect apurple color to the user. Thus, the Color Range of the blue color inthis example is about three and one-half degrees Celsius (i.e., fromabout 4.0° C. to about 7.5° C., but could start at about 5.0° C. andlast until about 8.5° C.). Finally, as the thermochromic liquid crystalscontinue to warm and change their orientation, at about 11.0° C. theystart to reflect no color to the user (because at that point the user isviewing the back layer of the strip). Thus, the Color Range of thepurple color in this example is about three and one-half degrees Celsius(i.e., from about 7.5° C. to about 11.0° C., but it might not startuntil 8.5° C. and last until about 12.0° C.). The combination of all theColor Ranges (i.e., the about 1 degree Celsius for red+the about 1degree Celsius for green+the 3.5 degrees Celsius for blue+the about 3.5degrees Celsius for purple) equals a “Color Display Range” of ninedegrees Celsius.

The Color Range of the blue color can be much longer than either theColor Range of the red color or the green color (partially because theearly blue color will still contain some green color). In fact, theColor Range of blue might be three or more times as long as the ColorRange for either the red color or the green color reflected by thethermochromic liquid crystals to the user. The same can be true for theColor Range for the purple color as it corresponds to the Color Range ofthe red color and/or the green color. It is not uncommon for one ofordinary skill in the art to not even refer to the purple colorreflected by the thermochromic liquid crystals, and instead when one ofordinary skill in the art refers to a blue color, she or he will bereferring to the combination of the blue color and the purple color.However, because the inventions described herein pertain to colors andshades of color, this application will occasionally distinguish betweenthe blue and purple colors reflected by the thermochromic liquidcrystals to the user of the prior art Indicator strips.

The problem with the prior art Indicator strips is that the colorvisible at the higher end of the thermochromic liquid crystals' ColorDisplay Range, which is the blue Temperature Range and/or the purpleColor Range, persists for longer than the proportional range of thelower temperatures (e.g., the Color Range for a red color and/or theColor Range for a green color), especially given the long blue ColorRange as it slowly changes from a green color, and slowly changes to apurple color, before all color reflection ends. By way of example only,if thermochromic liquid crystal is formulated so that the Color Play forthe red color and the green color equals two degrees Celsius (i.e., onedegree Celsius for red, plus one degree Celsius for green), when thatprior art Indicator strip moves from green to blue, the Color Range forthe blue color will last for at least three and one-half degrees Celsiusor more. Moreover, the Color Range for the purple color that follows theblue color will also last for at least three and one-half degreesCelsius or more.

In certain applications, these long lasting Color Ranges for the blueand purple colors may be so confusing to the user that the Indicator isof no use because the Color Display Range of that Indicator is too widefor a given use. By way of example only, if the Indicator is needed toindicate a Color Display Range that is just three degrees Celsius wide(by way of example only, the three degrees Celsius range of the PackingTemperature Range for vaccine), such an Indicator would be impossible tomanufacture with the current technology because although the Color Playof the red color and the green color would equal about two degreesCelsius, because of the operation of the thermochromic liquid crystal,the Color Range of the blue and purple colors would last at least threeand one-half degrees Celsius each. Consequently, the Color Display Rangefor that Indicator would be at least nine degrees Celsius (e.g., (aboutone degree Celsius Color Range for red)+(about one degree Celsius ColorRange for green)+(about three and one-half degrees Celsius Color Rangefor blue)+(about three and one-half degrees Celsius Color Range forpurple)=a Color Display Range of nine degrees Celsius)) rather than thedesired Color Display Range of three degrees Celsius.

These long persisting blue and purple Color Ranges are problematic forat least two reasons. First, thermochromic liquid crystals can only beformulated for a temperature resolution of about 0.5° C. Thus thenarrowest a Color Range for a red or green color can be is point-fivedegrees Celsius. And thus the Color Range for its corresponding blue andpurple colors would be about three-point-five times the Color Range ofred or green, or a Color Range of one-point-five degrees Celsius forblue and a Color Range of one-point-five degrees Celsius for purple.(Thus, it may be impossible to manufacture an Indicator that possesses aColor Display Range of only two degrees Celsius, because the red ColorRange plus the green Color Range would require a combined total ofone-point-zero degree Celsius, and the blue Color Range and the purpleColor Range would require one-point-five degree Celsius each; whichequals a Color Display Range of four-point-zero degrees Celsius (e.g.,(one-half degree Celsius for red)+(one-half degree Celsius forgreen)+(one and one-half degrees Celsius for blue)+(one and one-halfdegrees Celsius for purple)=a total of four degrees Celsius)) ratherthan the desired two degrees Celsius Color Display Range. Thus, there isa need for an Indicator that is able to at least partially block (orpossibly completely block) a given color's Color Range from beingreflected to the user of the Indicator so as to obtain an Indicator witha reduced Color Display Range.

It should be appreciated that this long Color Range associated with theblue color, and the long Color Range associated with the purple colorcreates another problem for the use of the prior art Indicator inconjunction with the PCM-filled panels (as well as for otherapplications). Specifically, because of the long Color Range of the bluecolor and the long Color Range of the purple color, the user could bemisled into thinking that the PCM-filled panels were within the desiredPacking Temperature Range (by way of example only, 2° C. to 5° C.)because a color indication (in the form of a blue color or purple color)was still visible in the Indicator. But in fact, because thecorresponding temperature of that blue color was 6° C. or 7° C. (andthus, outside the desired Packing Temperature Range) the temperature ofthe PCM material in the panel had already thawed and warmed to such apoint that there was not enough thermal energy left in each panel toprotect the Product being shipped in the cooler system.

For example, if the prior art Indicator was showing a purple color, theuser responsible for packing and shipping the temperature sensitiveproduct might understand that purple color to mean that the PCM-filledpanels were within the proper Packing Temperature Range for assembly andshipment. In reality, the purple color is an indication that the PCM hadalready melted to the point where the temperature of the PCM was 7° C.or higher. At that point, the cooling system containing the assembledsix PCM-filled panels would not have enough cooling energy left in thepanels to protect the temperature sensitive product being shipped in thecooling system from prolonged exposure to hot temperatures (known as“Super Thawing”). Consequently, that temperature sensitive product wouldbe rendered ineffective by an exposure to an excursion to a warmtemperature. Thus, there is a need for an Indicator that possesses a wayfor the Color Display Range displayed to the user to be narrowed.

This inability of the prior art Indicators to indicate temperatures in anarrow Color Display Range (by way of example only 3.0° C. or less)results in the next problem associated with these prior art Indicators,which is that in order to accurately indicate an Object was within adesired Color Display Range of just 3.0° C., the user must: i) employ anIndicator with at least two distinct sections that each provide its owncolor indication (i.e., the “Display Panels”); ii) each Display Panelmust contain its own distinct thermochromic liquid crystal formulation;and iii) the user must compare the color of a first Display Panel to thecolor of a second Display Panel, and make a cognitive decision regardingthe supposed temperature of the Object based on the differing colorsdisplayed by the two formulations in their respective Display Panels. Aswill be explained below, this prior art Indicator can be very confusingfor the user.

Referring to FIG. 1C and FIG. 1D, the prior art Indicator strip 120requires the use of a first collection of thermochromic liquid crystals125 contained in a first display panel 126 having its own formulation,so as to provide a color change at a first temperature, and requires theuse of a second collection of thermochromic liquid crystals 125 in asecond display panel 127 also having its own formulation different fromthat of the thermochromic liquid crystal 125 contained in the firstdisplay panel 126, so as to provide a notable color difference betweenthe first display panel 126 and the second display panel 127. The liquidcrystal formulations in each of the first panel 125 and the second panel126 differ in their Red Start temperature. In the prior art Indicatorstrip 120, the Red Start temperature for the liquid crystal formulationin the first display panel 126 is lower than the Red Start temperatureof the liquid crystal formulation in the second display panel 127. Thedifference between the Red Start temperature for the thermochromicliquid crystals in the first display panel 126 and the thermochromicliquid crystals in the second display panel 127 is by way of exampleonly about two to three degrees Celsius.

The prior art Indicator strip 120 in FIG. 1D also includes smallorientation squares 129 that are colored a certain color so as tocontrast with the color of the first display panel 126 and the color ofthe second display panel 127. The template 128 is used to visuallyseparate the first display panel 126 from the second display panel 127of the Prior Art Indicator strip 120 in their activated state. Theorientation squares 129 are located on top of the prior art Indicatorstrip 120 and are used by the end user to verify the orientation of theprior art Indicator strip 120, because without the orientation squares,the user would likely not know which of the display panels 125 and 126would be formulated to be the first Red Start color change.

As described herein, thermochromic liquid crystals can reflect differentcolors as they are heated or cooled. Below the Red Start temperature, aliquid crystal strip will appear black due to the backing layer beingcolored black. However, as the Indicator strip is heated above the RedStart temperature, the film will first appear red, then green, thenblue, and then purple until finally the Indicator strip becomes blackagain. Given that the prior art Indicator 120 strip in FIG. 1D containsa first display panel 126 and a second display panel 127, and eachdisplay panel can display several colors (black, red, green, blue andpurple), there are several possible color combinations that can bedisplayed by the prior art Indicator 120 depending on the temperaturethe prior art Indicator strip 120 is exposed to.

As described herein, the prior art Indicator strip 120 can be attachedto an Object so as to be used to determine the temperature of thatObject. When the Object to which the prior art Indicator strip 120 isattached is colder than the Red Start temperature of the liquid crystalformulations 125 contained in both the first display panel 126 andsecond display panel 127 of the prior art Indicator strip 120, bothdisplay panels 126 and 127 will appear black (as shown in FIG. 1D by thehash marks). Thus, if an Object were thawing from a freezing temperatureto a warmer temperature, the black color of the display panels 126 and127 would indicate to a user that the Object is at a temperature that islower than the Red Start temperature of the liquid crystal formulationsin the first display panel 126 and second display panel 127 and thus isnot within the Packing Temperature Range. Note that the color of thetemplate 128 (that provides shape and detail to the prior art Indicator)is also black; and therefore, when the temperature of the Object iscolder than the Red Start temperatures of the first display panel 126and the second display panel 127, no contrast is evident.

The Red Start temperature of the liquid crystal 125 formulation in thefirst display panel 126 coincides with a temperature of interest to theend user. The Red Start temperature of the liquid crystal 125formulation in the second display panel 127 coincides with a secondtemperature of interest to the end user. In general, the end user isinterested in determining whether the temperature of the Object 100 issupposedly within the Packing Temperature Range, which would be betweenthe Red Start temperatures of the first display panel 126 and the seconddisplay panel 127.

The prior art Indicator strip 120 is designed in such a way that when itis attached to an Object that has been frozen, several colorcombinations are observed when the Object thaws to a warmer temperature.For instance, as the temperature of the thawing Object rises beyond thestart-of-indication temperature of the first display panel 126 but isstill lower than the start-of-indication temperature of the seconddisplay panel 127, several color combinations are possible as shown inFIG. 1E. The first combination to appear as the temperature rises isshown by the prior art indicator strip 130 in FIG. 1E a, which shows thefirst display panel 136 appearing red (as denoted by the dots) and thesecond display panel 137 appearing black (as indicated by the hashmarks). Note that the color of the template 138 is black and thereforegood contrast is evident between the red color of the first displaypanel 136 and the template 138.

The second combination to appear as the temperature rises is shown bythe prior art Indicator 140 depicted in FIG. 1E, which shows the firstdisplay panel 146 appearing green (as denoted by the unfilled circles)and the second display panel 147 appearing dark (as indicated by thehash marks). Note that the color of the template 148 is black andtherefore good contrast is evident between the green color of the firstdisplay panel 146 and the template 148.

The third combination to appear as the temperature of the Object risesis shown by the prior art Indicator 150 in FIG. 1E c which shows thefirst display panel 156 appearing blue (as denoted by the diamond-shapedmarks) and the second display panel 157 appearing black (as indicated bythe hash marks); which supposedly indicates that the Object is withinthe desired Packing Temperature Range. Note that the color of thetemplate 158 is black and therefore good contrast is evident between theblue color of the first display panel 156 and the template 158.

The three color combinations displayed collectively in FIG. 1E a throughand including FIG. 1E c show that the temperature of the Object iswithin the Packing Temperature Range and is demarcated by the Red Starttemperatures of the first display panel 136, 146 and 156, when comparedto the color of the second display panel 137, 147 and 157, respectively.As such, the PCM-filled panels or Objects could be at the propertemperature for assembling the cooler system and shipping thetemperature sensitive product, supposedly without concern that: i) theassembled cooler system would Super Cool the temperature sensitiveproduct being shipped; or ii) the assembled cooler would lack enoughthermal energy to protect the Product being shipped against SuperThawing.

Although the operation of the prior art Indicator as describedcollectively in FIG. 1E a through and including FIG. 1E c is initiallydesirable because it appears that only a single display panel 136, 146and 156 would be needed to alert the user that the temperature of theObject was within the Temperature Packing Range, as described above, theColor Display Range over which liquid crystal films effectuate theirchange of Color Range from black to red, green, blue, purple and blackagain is so wide, it requires at least two display panels 126 and 127 tobe used. This shortcoming of thermochromic liquid crystal becomesobvious when the user desires to monitor the temperature over a ColorDisplay Range that is a very short (by way of example only, a ColorDisplay Range of three degrees Celsius). Therefore, if an Indicator ofthe type described in FIG. 1E a through and including FIG. 1E c isdesired that has a Packing Temperature Range of three degrees Celsius,because of the long persistence of the blue and purple colors throughtheir Color Range, the prior art Indicator 130 requires the use of theat least two panels to allow the user to discern whether the temperatureof the Object was still within the Packing Temperature Range.

This is why, as shown in FIG. 1E c, when the Object to which theIndicator is attached is thawing, a color combination is possible inwhich the first display panel 156 turns blue and/or purple while thesecond display panel 157 remains black or dark.

However, due to the persistence of the blue and purple colors over awide temperature range, the start-of-indication temperature of thesecond formulation of the liquid crystal 125 included in the seconddisplay panel 157 is set to coincide with the highest temperature in thetemperature range of interest to the user. Therefore, as the temperatureof the thawing Object continues to rise, several other colorcombinations are possible as shown by FIG. 1F so as to warn the userthat the temperature of the Object (e.g., the PCM-filled panel) hadexceeded the Packing Temperature Range.

For instance, the first color combination encountered as the temperaturerises beyond the Packing Temperature Range and causes the Red Starttemperature of the second display panel 167 to be visible, is shown bythe prior art Indicator 160 in FIG. 1F a, which shows the first displaypanel 166 showing a blue color (as indicated by the diamond-shapedmarks) and the second display panel 167 showing a red color (as shown bythe dots). Note that the second display panel 167 also contains themessage “NO!” to advise the user that even though a color is observed inthe first display panel 166 and in the second display panel 167, thetemperature of the Object being monitored is higher than the PackingTemperature Range. Because the color of the “NO!” message is black, itblends in with the black color of the second display panel when it hasnot yet reached a temperature that causes the thermochromic liquidcrystals to reflect a color (as shown in 137, 147 and 157), andtherefore the user cannot view that NO! message until the liquid crystal125 contained in the second panel 137 or 167 reaches its Red Starttemperature. Note that the color of the template 168 is also black, andtherefore as shown in FIG. 1F a, good contrast is evident between theblue color of the first display panel 166, the red color of the seconddisplay panel 167 and the black color of the template 168.

The second color combination encountered by the user as the temperatureof the Object rises above a desirable Packing Temperature Range, isshown by the prior art Indicator 170 in FIG. 1F b, which shows the firstpanel 176 showing a black color (as indicated by the hash marks) and thesecond display panel 177 showing a green color (as shown by the unfilledcircles). Note that the second display panel 177 contains the message“NO!” to advise the user that even though a color is observed in theprior art Indicator 170, the temperature is higher than the PackingTemperature Range. Note that the color of the mask 178 is black andtherefore good contrast is evident between the green color of the seconddisplay panel 177 and the template 178.

The third color combination encountered as the temperature rises beyondthe desirable Packing Temperature Range, which is evidence by the RedStart of the second display panel 187 being visible, is shown by theprior art Indicator 180 in FIG. 1F c, which shows the first displaypanel 186 showing a black color (as indicated by the hash marks) and thesecond display panel 187 showing a blue or purple color (as shown by thediamond-shaped marks). Note that the second display panel 187 containsthe message “NO!” to advise the user that even though a color isobserved, the temperature of the Object being monitored is higher thanthe temperature range of interest. Note that the color of the template188 is black and therefore good contrast is evident between the bluecolor of the second display panel 187 and the template 188.

A reprint of the user instructions for the interpretation of the twopanel prior art Indicator 120, 130, 140, 150, 160, 170 and 180 is shownin FIG. 1G, along with the instructions to possibly understand itsoperation.

What should be appreciated by the fact it took multiple paragraphs todescribe how prior art Indicators 120, 130, 140, 150, 160, 170 and 180function, is that the device is very cumbersome and difficult to usewhen determining whether or not the temperature of the Object is withinthe Packing Temperature Range, as evidenced by the confusing userinstructions at FIG. 1G. Moreover, because a first display panel 136 anda second display panel 137 are necessary in order for the user to beable to discern whether or not the Object is within the PackingTemperature Range, by default at least a first formulation and a secondformulation are required for the first display panel 136 and the seconddisplay panel 137, respectively, to convey the confusing message to theuser (i.e., the Object was or was not within the desired PackingTemperature Range).

It should also be appreciated that each formulation in each of the twodisplay panels 136 and 137 has a cost associated with manufacturing theformulation, applying the formulation to the cardboard, etc. Thus, byway of example only, it is desirable that an Indicator for certainembodiments have just a single display panel so as to: i) eliminate theneed to perform the cognitive steps associated with the use of multipledisplay panels so as to determine when the Object is within its PackingTemperature Range; ii) eliminate the need for orientation boxes so as tobe able to determine which is the first display panel and which is thesecond display panel; iii). eliminate the confusion associated with theuse of multiple display panels; and iv) reduce the cost associated withuse of multiple display panels.

It should also be appreciated that there are other prior art Indicatorsthat employ not just two, but three display panels in order to displayto the user whether the Object being monitored is within the PackingTemperature Range. In very simple terms and as shown in FIG. 1H, thethree display panel prior art Indicator 190 has a first panel 196containing an “X” to indicate, when it is visible, that the temperatureof the Object to which the three display panel prior art Indicator 190is attached is at too low of a temperature for the cooling system to beassembled and the Product packed into the cooling system. The seconddisplay panel 197 contains a “√” to indicate, when it is visible, thatthe Object is at the desired temperature (i.e., the PCM-filled panel iswithin the Packing Temperature Range for assembly into the coolingsystem). And the third display panel 198 contains an “X” to indicate,when it is visible, that the temperature of the Object (likely thePCM-filled panel) is too high for the cooling system to be assembled andthe Product being inserted into the assembled cooler system.

As with the two-panel prior art Indicator discussed above in regard toFIG. 1D, FIG. 1E and FIG. 1F, each of the formulations in the threedisplay panels 196, 197 and 198 are designed to interact with eachother, so as to provide a message to the user as to whether or not theObject was within its Packing Temperature Range. Thus, the three-panelprior art Indicator 190 has the same problems as the two-panelIndicator. By way of example only, one problem with the three panelprior art Indicator 190 is the fact that it contains three displaypanels 196, 197 and 198, and each display panel contains a separateliquid crystal formulation which has all the problems discussed herein.Moreover, the user of the three panel prior art Indicator 190 mustperform cognitive thinking and comparisons of the glyphs 199 displayedin the three display panels 196, 197 and 198 to properly determinewhether the Object whose temperature is being monitored (e.g., aPCM-filled panel) is at the proper temperature for assembly into thecooling system (i.e., within the Packing Temperature Range). Thus, itwould be advantageous to have a thermochromic liquid crystal Indicatorthat contains a single display panel, because such an Indicator would beeasier for the user to employ, and would be less expensive tomanufacture.

BRIEF SUMMARY OF INVENTION

Embodiments of the present inventions include Indicator(s) describedherein to, for example, achieve a more accurate indication or reflectionof the temperature of the Object to which the Indicator is attached orotherwise associated with by overcoming the problems common in the useand/or operation and/or construction of the currently available priorart Indicators as discussed above.

Embodiments of the inventions can, for example, be used to indicate thetemperature of the Object to which the Indicator is attached, or thetemperature of the environment surrounding the Object, and in doing somore accurately reflect to the person interested in the temperature ofthe Object, what the actual temperature of that Object is and/ortemperatures the Object has been subjected to. That Object could be byway of example only a device, a product, an insulating device, a person,and/or an article.

Embodiments of the inventions described herein can achieve this moreaccurate indication or reflection of the temperature of the Object towhich the Indicator is attached in at least the ways described herein,and do so either individually or collectively.

Embodiments of the inventions described herein can achieve more accurateindication or reflection of the temperature of the Object attached tothe Indicator or within an Object on which the Indicator is locatedwhile overcoming the problems common in the use and/or operation and/orconstruction of the currently available Indicators.

The present inventions and their related embodiments can overcomeproblems in the prior art by, for example, employing a novel Indicatorthat eliminates the effects of ambient air and/or the touching of theIndicator. The improvements presented by the inventive device arisesfrom various novel aspects, including one or more of the following: 1)the structure of the inventive device (which could include by way ofexample only, one or more of the following aspects: i) including a topcapsule for forming an air pocket; ii) a magnifying optic or amagnifying film for increasing the visual size of the glyph beingdisplayed by the liquid crystal either alone or in conjunction with atype of template or mask; and iii) an optic or optic film for increasingthe viewing angle of the message displayed by the liquid crystal layer);2) a thermo-insulative layer positioned on top of the liquid crystallayer and a thermal transmitting layer positioned below the liquidcrystal layer; 3) the positioning of the inventive devices on the Objectso that the inventive devices are preferably positioned in a manner thatthe impact of the ambient air on the operation of the thermochromicliquid crystal is minimized, including positioning the inventive devicesso that they are isolated from the air stream of the ambient airsurrounding the Object, as well as preferably positioning the inventivedevice so that it is closer to and can better reflect the coretemperature of the Object; 4) a template to display a message to theuser, the template comprised of at least two regions, one region beingfully and solidly colored and the other region being completely clear,wherein the template displays a message alternately when the colorsreflected by the liquid crystal layer to the user through thetransparent region of the template blend in with the colored region ofthe template at a first temperature, and the color of the templatecontrasting with certain other colors reflected by the liquid crystallayer to the user through the transparent portion of the template at asecond temperature; and 5) a mask that acts as a filter to block certaincolors from being reflected by the liquid crystal layer to the user at afirst temperature and allows certain other colors to pass through and beviewed by that user at a second temperature and that differs from thetemplate in that the mask is not solidly colored.

By isolating the inventive Indicator from the impact of the ambient airsurrounding both the Indicator and the Object, the inventive Indicatorprovides an indication of temperature that is more closely aligned withthe temperature of the Object, and more particularly is more closelyaligned with the temperature of the core of the Object, and lessreflective of the temperature of the surface of the Object beingmonitored.

An alternative embodiment of the present inventions could also containan improved liquid crystal formulation that aids in slowing theresponsiveness of the transition of the liquid crystals from oneorientation to a second orientation in response to a change intemperature, thereby slowing down the Color Change.

Another alternative embodiment of the present inventions could contain atemplate that displays a message to the user by alternately blending inwith certain colors reflected by the thermochromic liquid crystal layerto the user so as to cause the message to not be able to be seen by theuser when the thermochromic liquid crystal is within a certain ColorRange (at a first temperature), and then contrasting with certain othercolors reflected by the thermochromic liquid crystal layer so as tocause the message to be able to be seen by the user due to the contrastbetween the color of the template and the color of the thermochromicliquid crystal when it is within a different Color Range (at a secondtemperature).

Another embodiment of the present inventions could contain a mask (whichacts like a color filter) that aids in partially or completely blockingone or more Color Ranges from being displayed to the user, whileallowing other colors to pass through the filter and be viewed by theuser at a second temperature. This can be accomplished by selecting thecoloring of the top layer of the liquid crystal strip so as to create amask that is used to display a glyph or message to the user thatindicates that the Object is within the Packing Temperature Range (e.g.,by displaying a Color Range, displaying a glyph, or otherwise informingthe user that the product being monitored by the Object is ready or isnot ready for use), and such can be displayed because of either: i) thecolor or colors reflected off the thermochromic liquid crystal beingallowed to pass through a single portion mask at a first predeterminedtemperature, but then blocking other colors at a second predeterminedtemperature; or ii) the contrast created between a first color or colorsreflected off the thermochromic liquid crystal and being allowed to passthrough a first portion mask while that first portion of the masksimultaneously blocks or filters other colors, and a second color orcolors reflected off the thermochromic liquid crystal and being allowedto pass through a second portion of the mask at the same predeterminedtemperature while that second portion of the mask also simultaneouslyblocks or filters other colors.

More specifically, the colors displayed to the user by the Indicatorcould be narrowed, thereby causing a narrowing of the Color DisplayRange displayed to the user, by employing a template or a mask thatblocks, absorbs, filters or cancels out a particular color beingreflected by the thermochromic liquid crystal to the user. Thisblocking, absorption, filtering or cancelling out of the selected ColorRange so as to reduce the width of the Color Display Range could occuron either end of the temperature range displayed. Such blocking,absorption, filtering or cancelling out can result in the user notseeing the Color Range being filtered out. For example, if the Indicatorchanges color when it warms from red to green, and then changes colorfrom green to blue, and then blue to purple, if the blue and purplecolors are unfavored, by coloring a mask a certain color, that certaincolor will absorb most of the blue color and most of the purple color sothat most of the blue color (typically the blue hues appearing at theend of the blue Color Range) and most of the purple color are notdisplayed to the user of the Indicator and instead a black color isdisplayed. The certain color used in the mask also has the advantage ofallowing most of the red and green colors to pass through so that theuser can view those colors.

Eliminating a first color from being displayed to the user also has theadvantage of allowing the Color Range of a second color to be displayedto the user for a longer period of time because the formulation of theliquid crystal would be formulated to allow the second color to occur inthe same temperature that the first color occurred in. For example, ifan Indicator has a green color that is visible from 12° C. to 14° C.,and a blue color that is visible from 15° C. to 21° C. so that the greenColor Range is two degrees Celsius long, and the blue Color Range is sixdegrees Celsius long, if the blue Color Range is filtered out, thethermochromic liquid crystal could be formulated so that the green coloris visible at not only 12° C. to 14° C., but at 15° C. to 21° C. aswell, and then most of the blue color that would have a Blue Start atabout 22° C. is filtered out. This is desirable because a green colorwould be much easier for a user to understand as signaling the Objectbeing monitored is at the desired temperature.

An additional alternative embodiment of the present inventions couldcontain an Indicator that employs a single display panel, so as toeliminate the cost of generating and using multiple formulations ofliquid crystal. Doing so would also eliminate the confusion associatedwith the use of the prior art Indicators containing two or more displaypanels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side overhead view of a prior art PCM-filled panel with aprior art thermochromic liquid crystal strip or Indicator on its topsurface.

FIG. 1B is a side cross-sectional view of the prior art PCM-filled panelwith a prior art thermochromic liquid crystal strip or Indicator on itstop surface.

FIG. 1C is a side cross-sectional view of the prior art thermochromicliquid crystal strip or Indicator.

FIG. 1D is a top down view of a prior art thermochromic liquid crystalstrip or Indicator.

FIG. 1E a, FIG. 1E b, and FIG. 1E c are top down views of prior artthermochromic liquid crystal strips or Indicators.

FIG. 1F a, FIG. 1F b and FIG. 1F c are top down views of prior artthermochromic liquid crystal strips or Indicators.

FIG. 1G is a top down view of a prior art thermochromatic liquid crystalstrip or Indicator.

FIG. 1H is a three display panel prior art Indicator.

FIG. 2A is a close-up side cross-sectional view of the inventivethermochromic liquid crystal strip or Indicator and the prior artPCM-filled panel, with the inventive thermochromic liquid crystal stripor Indicator positioned on the top surface of the prior art PCM-filledpanel.

FIG. 2B is a close-up side cross-sectional view of the inventivethermochromic liquid crystal strip or Indicator and the prior artPCM-filled panel, with the inventive thermochromic liquid crystal stripor Indicator positioned in an indentation in the prior art PCM-filledpanel.

FIG. 3A is a close-up side cross-sectional view of the inventiveIndicator that includes an insulative layer or housing surrounding atleast the thermochromic liquid crystal strip, and which can bepositioned on the top surface of the prior art PCM-filled panel.

FIG. 3B is a close-up side cross-sectional view of the inventiveIndicator that includes an insulative layer or housing surrounding atleast the thermochromic liquid crystal strip, and which can bepositioned in an indentation in the prior art PCM-filled panel.

FIG. 3C is a close-up side cross-sectional view of the alternativeembodiment of the inventive Indicator that includes an insulative layeror housing surrounding at least the thermochromic liquid crystal strip,and which can be positioned in an indentation in the prior artPCM-filled panel.

FIG. 3D is a close-up side cross-sectional view of the alternativeembodiment of the inventive Indicator that includes an insulative capcovering at least the thermochromic liquid crystal strip, and which canbe positioned in an indentation in the prior art PCM-filled panel.

FIG. 3E is a close-up side cross-sectional view of an alternativeembodiment of the inventive Indicator that includes an insulative layeror housing that surrounds at least the thermochromic liquid crystalstrip, and which contains a pressure fit sealing disc as part of theinsulative body, all of which can be positioned in an indentation in theprior art PCM-filled panel.

FIG. 3F is a close-up side cross-sectional view of an alternativeembodiment of the inventive Indicator that includes an insulative layeror housing that surrounds at least the thermochromic liquid crystalstrip, and which contains a pressure fit sealing disc used inconjunction with a sealing O-ring as part of the insulative body, all ofwhich can be positioned in an indentation in the prior art PCM-filledpanel.

FIG. 4A is a close-up side cross-sectional view of an alternativeembodiment of the inventive Indicator that includes a magnifying opticpositioned above the thermochromic liquid crystal strip and positionedinside an insulative layer or housing that surrounds at least thethermochromic liquid crystal strip, and which can be positioned in anindentation in the prior art PCM-filled panel.

FIG. 4B is a close-up side cross-sectional view of an alternativeembodiment of the inventive Indicator that includes a magnifying opticpositioned as part of the insulative layer or housing that surrounds atleast the thermochromic liquid crystal strip, and which can bepositioned in an indentation in the prior art PCM-filled panel.

FIG. 5 is a side cross-sectional view of the inventive thermochromicliquid crystal strip or Indicator showing the mask that can be used toconvey a message to the user, positioned on top of the thermochromicliquid crystal strip or Indicator.

FIG. 6A is both an overhead view and a listing of the representations ofthe colors and messages displayed by the single portion template thatcould be positioned on top of or as part of the thermochromic liquidcrystal strip that shows how the message conveyed by the template can betransmitted to the user depending on the temperature of thethermochromic liquid crystal Indicator.

FIG. 6B is both an overhead view and a listing of the representations ofthe colors and messages displayed by the multiple portion mask thatcould be positioned on top of or as part of the thermochromic liquidcrystal strip that shows how the message conveyed by the mask can betransmitted to the user depending on the temperature of thethermochromic liquid crystal Indicator.

FIG. 6C is a listing of many of the possible positive messages that canbe conveyed to the user by use of the template or the mask inconjunction with the color changes of the thermochromic liquid crystalstrip or Indicator.

FIG. 6D is a listing of many of the possible negative messages that canbe conveyed to the user by use of the template or the mask inconjunction with the color changes of the thermochromic liquid crystalstrip or Indicator.

FIG. 6E is both an overhead view and a listing of representations of thecolors displayed by a single mask that could be positioned on top of oras part of the thermochromic liquid crystal strip that shows how theindication or message conveyed by the mask can be transmitted to theuser depending on the temperature of the thermochromic liquid crystalIndicator.

FIG. 7A is a top side view of a new embodiment of the PCM-filled panelcontaining the inventive thermochromic liquid crystal strip orIndicator.

FIG. 7B is a top view of a new embodiment of the PCM-filled panelcontaining the inventive thermochromic liquid crystal strip orIndicator.

FIG. 8 is a side cross-sectional view of the inventive thermochromicliquid crystal strip or Indicator containing a film that possesses orprovides improved viewing angle capabilities.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It should be noted that the present inventions disclosed herein, alongwith their various embodiments, pertain to the art of temperaturesensitive liquid crystals, their inclusion in a novel Indicator, and thevarious embodiments of those Indicators. Although the temperaturesensitive liquid crystals include a large class of chemicals, includingby way of example only thermochromic liquid crystals, thermotropicliquid crystals, cholesteric liquid crystals and cholesteric nematicliquid crystals, for the sake of convenience only, this application willfocus in this detailed description on the thermochromic type of liquidcrystals, although the other types of liquid crystals could be used aswell.

Referring initially to FIG. 1A and FIG. 1B, there is shown a prior artPCM-filled panel 100, and positioned on the top layer 105 of thePCM-filled panel 100 is a prior art thermochromic liquid crystal stripor Indicator 120. The prior art PCM-filled panel 100 may include severalindentations, including top indentations 110 in the top layer 105 andbottom indentations 118 in the bottom layer 115 of the PCM-filled panel.The top layer 105 of the PCM-filled panel 100 can also contain ahandhold 112 for moving the PCM-filled panels 100 in and out of thecooler box (not pictured) into which they are packed so as to allow abetter fit when the PCM-filled panels 100 are assembled in the cooler,the PCM-filled panels 100 may have beveled edges 130.

As shown in FIG. 1C and FIG. 1D, the prior art Indicator 120 can includeat least a template 128 that is positioned on the top surface 104 of thetop layer 121 of the prior art Indicator 120, a top layer 121 that facesthe user of the strip 120 and is typically positioned below the template128 (although the position of the top layer 121 and the template 128could be reversed in that the template 128 could be applied to thebottom side of the top layer 121), a bottom layer 123 that typicallyfaces the surface of the Object being monitored, and a middle layer 122that is formed by the top layer 121 and the bottom layer 123. Thismiddle layer 122 is the region where the prior art thermochromic liquidcrystal 125 is contained. The middle layer 122 of the thermochromicliquid crystal strip 120 could contain more than one compartment. Forexample, as shown in FIG. 1A and FIG. 1D and as discussed herein, thereis a first compartment 126 containing a first formulation ofthermochromic liquid crystal 125, and a second compartment 127containing a second formulation of thermochromic liquid crystal 125.

An adhesive layer 124 is typically applied to the side of the bottomlayer 123 facing away from the thermochromic liquid crystal 125, and istypically used to attach the thermochromic liquid crystal strip 120 tothe Object. A template 128 is typically applied (typically by painting,etc.) onto at least a portion of the top surface 104 of the top layer121 so as to allow the user to differentiate between the firstcompartment 126 and the second compartment 127, although the template128 can also be described to extend across both the first compartment126 and the second compartment 127, or to convey a message to the user(see FIG. 1F).

As discussed herein, the prior art thermochromic liquid crystal strip120 has several problems associated with its use. More particularly, asdescribed herein and as illustrated in FIG. 1D through FIG. 1F, as wellas in regard to FIG. 1G, the prior art Indicators 120 can be confusingto use because of the multiple colors displayed that must be compared toeach other and the user must make a cognitive decision so as todetermine whether the Object was within its Packing Range Temperature.The fact that multiple formulations are used in each Indicator, and eachformulation has an associated manufacturing cost, means that the priceof prior art Indicators include the costs associated with multipleliquid crystal formulations.

The use of two formulations so as to convey the message (i.e., indicate)that the PCM-filled panel at issue had reached the proper temperatureand that it could be assembled into a cooler system for use in shippinga temperature sensitive product, is not economically advantageous.Moreover, the message conveyed by the template 128 and the displaypanels 126 and 127 of prior art Indicator 125 (as discussed herein inrelation to FIG. 1D through FIG. 1G) is confusing and difficult tounderstand. These problems and shortcomings are even more obvious whenthe thermochromatic liquid crystal Indicator 190 contains three displaypanels 196, 197 and 198 as discussed above and as illustrated in FIG.1G.

Another problem associated with the prior art Indicators 120 and 190 isthe lack of a thermo-insulative portion or top layer to protect theIndicator 120 from being impacted by external influences, such asambient air flow or being touched by the user. Similarly, the prior artIndicator 120 lacks a thermo-responsive or thermo-conductive bottomlayer that would better transfer the thermal energy from the PCM-filledpanel 100 to the liquid crystal layer 125. Without such features, theprior art thermochromic liquid crystal strip 120 is exposed to externalforces that result in either a less accurate indication of thetemperature of the Object to which the Indicator 120 is attached, or aninaccuracy that needs to be accommodated for in the design of theIndicator containing the present inventions discussed herein.

To overcome the problems with the prior art Indicator 120 and thePCM-filled panel, in accordance with the purpose of the inventions asembodied, and both broadly described and illustrated herein, shown inFIG. 2A and FIG. 2B are one of the embodiments of the inventionsdisclosed herein. Specifically, FIG. 2A shows a novel Indicator strip200 (also referred to herein more particularly as the thermochromicliquid crystal structure or “novel Indicator structure” 255), which caninclude a top layer 240, a backing layer 260 and a compartment 250between the top layer 240 and the backing layer 260 that contains thethermochromic liquid crystal 251 and may contain either a template 228or a mask 228. As disclosed herein, each of these portions of either theIndicator 200 or the Structure 255 may contain a single novelimprovement or component, or multiple novel improvements or componentsthat improve the operation of the entire Indicator 200.

Because of the nature of the thermochromic liquid crystal 251, a colorchange can occur when the thermochromic liquid crystal 251 is exposed tocertain predetermined temperatures. As is known in the art and asdisclosed in (by way of example only) U.S. Pat. No. 3,965,742, which isfully incorporated herein by reference in its entirety, a thermotropicor a thermochromic liquid crystal can be formulated and manufactured toproduce a predetermined color at a predetermined temperature.

In regard to the present embodiment illustrated in FIG. 2A, the color ofthe thermochromic liquid crystal 251 can be viewed through the top layer240 as the thermochromic liquid crystal 251 changes from one color toanother in reaction to the changes in temperature. Both the top layer240 and the backing layer 260 should, for certain embodiments, beconstructed of a strong, resilient leak-proof material, such as plasticor other polymer material, so as to provide for the twisting or bendingthat might occur during transportation of the Object or the Productwithout tearing, breaking or leaking. The top layer 240 and the backinglayer 260 may also be made of a material that preferably allows the toplayer 240 and the backing layer 260 to be joined and sealed together,such as by heat stamping or other suitable means, although such sealingmay not be not necessary. The top layer 240 and the backing layer 260can both approximate the length and width of the liquid crystalcompartment 250, although variations in these dimensions are within thescope of the present invention. The top layer 240 can preferably be madeof a clear material, such as plastic, so that the user of the novelIndicator 200 can view at least some portion of the thermochromic liquidcrystal 251 contained in the liquid crystal compartment 250. The toplayer 240 should preferably, for certain embodiments be able to acceptpaint or ink so as to allow for coloring of a portion of the top layer240 so as to allow a mask 228 or a template 228 to be created asdiscussed herein with regard to FIG. 5 and FIG. 6A.

At least some portion of the top layer 240 can be engineered to be ableto accept paint or ink for coloring to form either a template 228 or amask 228. In the case of using a template or mask 228, it is preferablethat at least some portion of that top layer 240 remain free from ink orcoloring so that the user of the novel Indicator structure 255 canobserve the thermochromic liquid crystal 251 contained in the liquidcrystal compartment 250 through the clear portion of the top layer 240.It will be understood by one of ordinary skill in the art that thetemplate 228 could be applied to the bottom side 242 of the top layer240, as well as to the top side 241 of the top layer 240 (as isdescribed herein). By comparison, if a mask 228 is used in a givenembodiment, as described in more detail hereinafter with regard to themask 675 illustrated in FIG. 6B and discussed herein, it is preferablethat all of the area of the top layer 240 assigned to the mask 675 havesome ink or coloring so that the user of the novel Indicator structure255 can observe the interaction of the colors reflected by thethermochromic liquid crystal 251 contained in the liquid crystalcompartment 250 through the region of the top layer 240 reserved for themask 675, and as further described herein.

Moreover, the top layer 240 can contain one or more of any well knowncomponents or ingredients that promote thermal insulation, so as tothermally insulate the thermochromic liquid crystal 251 from the effectsof the user touching the novel Indicator structure 255 and/or from theeffects of airflow and/or ambient air surrounding the novel Indicatorstructure 255. Including an ingredient that promotes thermal insulationfrom the effects of airflow and/or ambient air surrounding thecomposition of the top layer 240 aids in ensuring that the novelIndicator structure 255 can more properly reflect and indicate thetemperature of the Object to which the novel Indicator structure 255 isattached, wherein the Object could be the PCM-filled panel 201.

The bottom side 261 of the bottom layer 260 should, for certainembodiments, also be able to accept paste, glue or other suitableadhesive for attaching the novel Indicator structure 255 to the Objectwhich the novel Indicator structure is monitoring, such as thePCM-filled panel 201. Moreover, the backing layer 260 can be comprisedof ingredients that lack insulative properties so as to promote thetransmission of the temperature of the Object to which the backing layer260 can be attached (such as the PCM-filled panel 201) to thethermochromic liquid crystal layer 250, so as to more accurately reflectthe temperature of the Object.

Another embodiment of the inventions disclosed herein that overcomes theproblems associated with the prior art Indicator strip 120 and the priorart PCM-filled panel 201 includes the modification of the liquid crystal251 contained in the liquid crystal layer 250 so as to include anadditive that aids in slowing down the response of the liquid crystal251 to changes in temperature. By changing the responsiveness and speedat which the liquid crystal changes its spatial orientation, so that theliquid crystal changes its spatial orientation more slowly, the colorreflected back to the user of the novel Indicator 200 will change to adifferent color more slowly. In this way, the novel Indicator 200 may beless influenced by the user touching the novel Indicator structure 255,and/or will be less influenced by the impact of ambient air impactingthe novel Indicator structure 255. Consequently, the novel Indicator 200can provide the user with a more accurate indication of the temperatureof the Object, such as the PCM-filled panel 201.

As shown in FIG. 2B, the novel Indicator structure 255 has been sized soas to fit into one of the top indentations 210 (or alternatively one ofthe bottom indentations 220) in the prior art PCM-filled panel 201.There are several advantages to sizing the novel Indicator structure 255to fit within one of the top indentations 210 or bottom indentations220. An advantage to sizing the novel Indicator structure 255 to fitwithin one of the top indentations 210 or bottom indentations 220 isthat it aids in moving the novel Indicator structure 255 out of thesurrounding airflow and/or ambient air. Moving the novel Indicatorstructure 255 out of the surrounding airflow and/or ambient air canenable the thermochromic liquid crystal 251 to more accurately reflectthe temperature of the Object to which the novel Indicator structure 255can be attached (e.g., the PCM-filled panel 201). Another advantage tosizing the novel Indicator structure 255 to fit within one of the topindentations 210 or bottom indentations 220 is that such sizing canenable moving the novel Indicator structure 255 out of the top or bottomplane of the PCM-filled panel 201 so that the novel indicator structurecan be protected from damage (e.g., scratching or impact) that wouldotherwise be inflicted on the novel Indicator structure 255 if it werepositioned on the top plane of the Object 201. Moreover, as discussedherein, moving the novel Indicator structure 255 into one of theindentations 210 or 220 can enable the novel Indicator 200 (includingthe novel Indicator structure 255) to be in closer contact with the coretemperature of the Object (e.g., the PCM contained in the PCM-filledpanel 201). By being closer to the core temperature of the PCM, thenovel Indicator 200 better and more accurately indicates the overalltemperature of the Object.

FIG. 3A through FIG. 3F illustrate alternative embodiments of the novelIndicator structure 255 described in FIG. 2A and FIG. 2B, wherein theIndicator 300 displayed in FIG. 3A through FIG. 3F contains the variousaspects and structural advantages described above in relation to FIG. 2Aand FIG. 2B and incorporated herein in full, but also containsadditional aspects so as to result in new embodiments.

One of the additional aspects illustrated in FIG. 3A through FIG. 3Bthat results in new embodiments of the novel Indicator 300 is the use ofan insulative cap 370 that covers at least a portion, and preferablycovers the entirety, of the novel Indicator structure 355. As shown inFIG. 3A through FIG. 3F, the novel Indicator structure 355 can includethe mask 328, the top layer 340, the backing layer 360, and theresulting thermochromic liquid crystal compartment 350 that contains thethermochromic liquid crystal 351. All these components of the novelIndicator structure 355 can contain some or all of the improvementsdiscussed above for the novel Indicator structure 255 (and by way ofexample only, can further contain an insulative component for the toplayer 340 such that the top layer 340 is insulative, a dopant that slowsthe responsiveness of the thermochromic liquid crystal 351 contained inthe thermochromic liquid crystal layer 350, and may not contain athermally conductive component in the bottom layer 360 such that thebottom layer is not thermally conductive).

The purpose and benefit of using the insulative cap 370 is to furtherinsulate the novel Indicator structure 355, including especially thethermochromic liquid crystal 351, from being touched by a user and/orfrom being impacted by the ambient air flow that would otherwisesurround and impact the accuracy of the novel Indicator structure 355,so as to provide better indication of the core temperature of the Object(e.g., the phase change material contained in the PCM-filled panel 301).

The insulative cap 370 is preferably made of a clear material, such asplastic, so that the user of the novel Indicator 300 can view at leastsome of the color reflected by the thermochromic liquid crystal 351contained in the novel Indicator structure 355. Although any materialcould be used to fill the space 371 between the insulative cap 370 andthe novel Indicator structure 355, for purposes of effectiveness ofcarrying out the present invention in conjunction with economies ofscale, the space 371 could simply be filled with air. Alternatively, thespace 371 could be manufactured so as to contain a vacuum, which wouldprovide the best possible insulation from external thermal impact, orcould be filled with any other material known to one of ordinary skillin the art such as Nitrogen, so as to provide effective insulation whilemaintaining the transparency necessary to view the thermochromic liquidcrystal 351.

Although FIG. 3A and FIG. 3B show the novel Indicator structure 355being attached directly to the top side 305 of the PCM-filled panel 301,and depicts the insulative cap 370 being attached directly to the topside 305 of the PCM-filled panel 301 as well, it is possible thatsimilar embodiments could be constructed where the insulative cap 370can include a floor portion (not shown) to which the thermochromicliquid crystal novel Indicator structure 355 could be attached. Thatfloor portion (not shown) could be attached to the insulative cap 370 bysnap fitting, gluing or any other attaching mechanisms, and the entireresulting assembly being attached to the top side 305 of the PCM-filledpanel 301 (or attached to the bottom side 315 of the PCM-filled panel301), by gluing or other adhesive mechanisms.

As shown in FIG. 3B, the novel Indicator structure 355 has been sized soas to fit into one of the existing top indentations 310 in the prior artPCM-filled panel 301 (or alternatively one of the bottom indentations320 contained in the bottom side 315 of the PCM-filled panel 301). Thereare several advantages to sizing the novel Indicator structure 355 tofit within one of the top indentations 310 or bottom indentations 320.One such advantage is that it aids in moving the novel Indicatorstructure 355 out of the touch of the user and/or out of the surroundingairflow and/or ambient air. Protecting the novel Indicator structure 355in this manner can enable the thermochromic liquid crystal 351 to moreaccurately reflect the temperature of the Object to which the novelIndicator structure 355 is attached (e.g., the PCM-filled panel 301).Another advantage to sizing the novel Indicator structure 355 to fitwithin one of the top indentations 310 or bottom indentations 320 isthat it moves the novel Indicator 300 out of the plane of the PCM-filledpanel 301 so that it can be protected from damage (e.g., scratching orimpact) that would otherwise be inflicted on the novel Indicator 300 ifthe novel Indicator were on the top plane of the Object. Moreover, asdiscussed herein, moving the novel Indicator structure 355 into one ofthe indentations 310 or 320 allows the novel Indicator structure 355 tobe in closer contact with the core temperature of the Object (e.g., thePCM contained in the PCM-filled panel 301). By being closer to the coretemperature of the PCM, the novel Indicator structure 355 better andmore accurately indicates the temperature of the Object.

An alternate embodiment to the embodiment shown in FIG. 3A and FIG. 3Bis illustrated in FIG. 3C, where the shape of the insulative cap 370from FIG. 3A and FIG. 3B is modified so as to match the dimensions ofone of the top indentations 310 or alternatively one of the bottomindentations 320. A benefit from forming this insulative cap 374 tomatch the dimensions of one of the top indentations 310 or alternativelyone of the bottom indentations 320 as closely as possible is that theinsulative cap 374 can further reduce the amount of airflow over andaround the novel Indicator structure 355. As explained herein, reducingthe amount of airflow over and around the novel Indicator structure 355can enable the thermochromic liquid crystal 351 to better match thetemperature of the core of the Phase Change Material within thePCM-filled panel 301.

As mentioned herein, the top portion 372 of the insulative cap 374 ispreferably sized so as to be slightly below the plane of the top layer305 of the PCM-filled panel 301 so as to prevent the insulative cap 374from getting scratched or damaged, as such damage or scratching cannegatively impact the use and operation of the novel Indicator 300. Theoperation of the insulative cap 374 may even be better improved if asealant 373, such as silicone or other sealing material, were used toeven better isolate the Structure 355, and more particularly betterisolate the thermochromic liquid crystal 351, from the touch of the userand/or the ambient air and airflow surrounding the PCM-filled panel 301,so as to better allow the novel Indicator structure 355 and moreparticularly the thermochromic liquid crystal 351 to match thetemperature of the core of the Phase Change Material within thePCM-filled panel 301. Moreover, as discussed herein, moving the novelIndicator 300 into one of the indentations 310 or 320 allows the novelIndicator 300 (including the novel Indicator structure 355) to be incloser contact with the core temperature of the Object (e.g., the PCMcontained in the PCM-filled panel 301). By being closer to the coretemperature of the PCM, the novel Indicator 300 better and moreaccurately indicates the temperature of the Object.

Although FIG. 3C shows the thermochromic liquid crystal novel Indicatorstructure 355 being attached directly to the top side 305 of thePCM-filled panel 301, and depicts the insulative cap 374 as directlytouching the top side 305 of the PCM-filled panel 301, it is possiblethat similar embodiments could be constructed where the insulative cap374 contains a floor portion (not shown) to which the Structure 355could be attached. That floor portion (not shown) could be attached tothe insulative cap 374 by snap fitting, gluing or any other usefulmeans, and the entire resulting assembly being attached to the top side305 of the PCM-filled panel 301 (or attached to the bottom side 315 ofthe PC-filled panel 301), by gluing or other means.

An alternate embodiment to the embodiments shown in FIG. 3A, FIG. 3B andFIG. 3C is illustrated in FIG. 3D, wherein the insulative cap 370 or 374of FIG. 3A, FIG. 3B and FIG. 3C can be replaced with an insulative sheet380 that aids in further reducing the amount of airflow over and aroundthe thermochromic liquid crystal Structure 355. Alternatively, althoughnot depicted, the insulative cap 370 or insulative cap 374 could be usedin conjunction with the insulative sheet 380. This insulative sheet 380,which allows novel Indicator structure 355, and more particularly thethermochromic liquid crystal 351, to better match the temperature of thecore of the phase change material within the PCM-filled panel 301because the insulative sheet 380 allows the novel Indicator structure355, and more particularly the thermochromic liquid crystal 351 to beisolated from the airflow and ambient air that enters the topindentations 310 and/or the bottom indentations 320. The space 371created by covering the top indentations 310 and/or bottom indentations320 could be filled with any of the materials discussed herein or knownin the art to provide insulative effects. Moreover, as discussed herein,moving the novel Indicator structure 355 into one of the indentations310 or 320 allows the novel Indicator structure 355 to be in closercontact with the core temperature of the Object (e.g., the PCM containedin the PCM-filled panel 301). By being closer to the core temperature ofthe PCM, the novel Indicator structure 355 better and more accuratelyindicates the temperature of the Object.

An alternate embodiment to the embodiment shown in FIG. 3A through FIG.3D is shown in FIG. 3E, where a novel Indicator housing 361 ispositioned into one of the indentations 310 or 320. The novel Indicatorhousing 361 contains a floor portion 362 upon which the novel Indicatorstructure 355 sits. The novel Indicator housing 361 can be apolypropylene, such as Achieve 1605 from Exxon Mobil. The housingmaterial is preferably comprised of a material that is: 1)injection-moldable (thermoplastic); 2) low-cost/commonly available; and3) of suitable modulus to snap fit to the disc 381.

Furthermore, the floor portion 362 of the novel Indicator housing 361should, for certain embodiments be thermoconductive so as to transferthermal energy from the Object (e.g., the PCM-filled panel) to theliquid crystal 351 contained in the novel Indicator structure 355.

Moreover, the shape of the novel Indicator housing 361 is modified so asto match the dimensions of one of the top indentations 310 oralternatively one of the bottom indentations 320. A benefit from formingthis novel Indicator housing 361 to match the dimensions of one of thetop indentations 310 or alternatively one of the bottom indentations 320as closely as possible is that it further reduces the amount of airflowover and around the novel Indicator structure 355. As explained herein,reducing the amount of airflow over and around the novel Indicatorstructure 355 can enable the thermochromic liquid crystal 351 to bettermatch the temperature of the core of the Object to which the novelIndicator structure 355 is attached (e.g., the Phase Change Materialwithin the PCM-filled panel 301).

To avoid the scratching that might occur to the top sheet from FIG. 3D,the novel Indicator housing 361 contains a top disc 381 that can berecessed below the plane of the top level 305 of the PCM-filled panel301. The disc 381 can be a 3-mm thick mar-resistant acrylic, such asACRYLITE® Optical mar resistant, sheet, Colorless 0A000 MR2 fromEvonik). Clear acrylic can be selected over polycarbonate, because thepolycarbonate can age and yellow over time. Preferably the mar resistantdisc 381 can be placed in the novel Indicator housing 361 with the marresistance towards the outside, which allows the mar resistance of thedisc 381 to maintain the optical function of the indicator even as theindicator is repeatedly reused and exposed to handling that mightscratch an unprotected acrylic. The thickness of the disc 381 does notaffect the function of the novel Indicator 300, but can provide someUV-blocking that can help stability of the Indicator. Recessing the disc381 slightly below the plane of the top layer 305 of the PCM-filledpanel 301 can prevent the disc 381 from getting scratched or damaged; assuch damage or scratching can negatively impact the use and operation ofthe novel Indicator 300.

An alternative housing that can self-seal the acrylic disc or otheracrylic viewing window could be manufactured using a soft, elastomericresin, for example Santoprene 101-55 or Santoprene 101-64. In this case,an acrylic disc with a diameter slightly larger than the opening of theinjection molded housing should, for certain embodiments be used. Thehousing then can be stretched within its elastic strain region aroundthe acrylic disc such that the stretched housing exerts a normal forceon the perimeter of the acrylic disc. The pressure applied to theperimeter of the acrylic disc can create a moisture-resistant seal.

The use of a novel Indicator housing 361 may be further improved if asealant 373, such as silicone or other sealing material, were used toeven better isolate the Structure 355 by sealing up the opening 310between the side walls of the insulative cap 376 and the upper walls ofthe PCM-filled Panel 301, and more particularly better isolate thethermochromic liquid crystal 351, from the touch of the user and/or theambient air and airflow surrounding the PCM-filled panel 301, so as tobetter allow the novel Indicator structure 355 and more particularly thethermochromic liquid crystal 351 to match the temperature of the core ofthe Phase Change Material within the PCM-filled panel 301. Moreover, asdiscussed herein, moving the Indicator 300 into one of the indentations310 or 320 allows the novel Indicator 300 (including the thermochromicsliquid crystal novel Indicator structure 355) to be in closer contactwith the core temperature of the Object (e.g., the PCM contained in thePCM-filled panel 301). By being closer to the core temperature of thePCM, the novel Indicator 300 better and more accurately indicates thetemperature of the Object.

As shown in FIG. 3F, to aid in eliminating the possibility thatcondensation could enter into the interior of the novel Indicator 300,an O-ring 335 could be placed between the bottom of the disc 381 and theupper edge 382 of a housing wall 330. Note that the upper edge 382 ofthe housing wall 330 can hold the disc 381 in place and pull the disc381 down to compress the O-ring 335 so as to create a moisture resistantseal.

This O-ring 335 could also aid in reducing the negative effect of theambient air flow on the accuracy of the Structure 355 and moreparticularly the thermochromic liquid crystal 351. The O-ring can be a50 to 70 durometer. Preferably, the O-ring should, for certainembodiments match the color of the housing 331, such that the O-ring 335does not distract from the Indicator. Although the top disc 381 could beheld in place by the upper edges 382 of the housing wall 330, the topdisc 381 could also be attached by snap fitting or by any otherattaching mechanism, such as gluing.

A double-sided tape, such as 3M (#9087), can be used to adhere thebottom surface 384 of the housing 383 to a top surface 305 of one of thetop indentations 310 or alternatively to the top surface 315 of one ofthe bottom indentations 320. The thickness of the tape can be about 10mils so as to be thick enough to fill in any unevenness in the panelsurface 305 or 315. Further, the tape could for example have a thermallyconductive capability to transfer thermal energy into the housing 383.In an alternative, a thermally conductive glue can be used instead oftape.

FIG. 4A and FIG. 4B illustrate an alternative embodiment of theinventive Indicator described herein, wherein the Indicator 400 containsthe various aspects described above in relation to FIG. 2A and FIG. 2Bas well as FIG. 3A through FIG. 3F, but also contains additionaloptional aspects so as to result in a new embodiment. One of theadditional aspects illustrated in FIG. 4A and FIG. 4B is use of an opticdevice 480 and 490 to magnify the color and/or message presented by theStructure 455, and more particularly the thermochromic liquid crystal451.

In the embodiment shown in FIG. 4A, the optic 480 can be placed atop thetop layer 440 and the mask 428 or template 428 of the novel Indicatorstructure 455, but below the insulative cover 470 of the novelIndication 400. Alternatively, as shown in FIG. 4B the optic device 490could be embedded or formed as part of the insulative cap 470.Preferably, if the optic device 490 can be formed as part of theinsulative cap 470, the top portion 492 of the optic device 490 wouldpreferably be below the plane of the top layer 405 of the PCM-filledpanel 401 so as to prevent damage to or scratching of the optic device490.

The optic device 480 and 490 could be formed by any material thatprovides magnification of the message generated by the interaction ofthe mask 428 positioned on the top layer of the top portion 440 of thenovel Indicator structure 455 in conjunction with the thermochromicliquid crystal 451 and as further explained herein regarding thedescription of FIG. 5. For example, the optic devices 480 and 490 ofFIGS. 4A and 4B could be formed using a clear plastic semi-circle shapeddome that can be filled with a liquid, gel or air or any other materialso long as it aids in the magnification of the message displayed by theinteraction of the mask 428 and the thermochromic liquid crystal 451.Alternatively, the optic device 480 and 490 could be comprised ofplastic or glass or similar material that when formed correctly,provides a magnification of the material underneath it.

The optic device 490 can be used in the inventive novel Indicator 400because it can enable the novel Indicator 400 to be smaller than itwould otherwise be, thereby allowing the novel Indicator 400 to fit intothe top indentation 410 or the bottom indentation 420 without a loss ofthe ability of the user to view the message displayed by the interactionof the mask 428 or template 428 with the thermochromic liquid crystal451. As discussed herein, allowing the novel Indicator structure 455 tobe at least partially and preferably wholly removed from the airflowand/or ambient air surrounding the PCM-filled panel 401 can enable thenovel Indicator structure 455 and more particularly the thermochromicliquid crystal 451 to better match the temperature of the phase changematerial within the PCM-filled panel 401. Moreover, as discussed herein,moving the novel Indicator 400 into one of the indentations 410 or 420can enable the novel Indicator 400 to be in closer contact with the coretemperature of the Object (e.g., the PCM contained in the PCM-filledpanel 401). By being closer to the core temperature of the PCM, theIndicator 400 better and more accurately indicates the temperature ofthe Object.

21. FIG. 5 illustrates components of the novel Indicator structure 555as it sits in relation to the mask 528 or template 528. The use of amask 528 or template 528 not only conveys the message(s) to the userabout the state of the temperature of the Object (e.g., the PCM-filledpanel), but the mask 528 (as further described herein in conjunctionwith the illustrations in FIG. 6B) in certain embodiments narrows therange of the color reflected by the thermochromatic liquid crystal 551positioned in the liquid crystal compartment 550 to the user. Bynarrowing the range of the colors displayed to the user, the novelIndicators 200, 300 and 400 can have a much narrower range oftemperature, as measured by the Color Display Range, to be monitored anddisplayed to the user. Thus, the novel Indicators 200, 300 and 400discussed herein, should be understood to employ the embodiments of thetemplate 528 or mask 528 discussed herein in regard to FIG. 5 and thetemplate 625 or mask 635 discussed herein in regard to FIG. 6A thoughFIG. 6D.

Such narrowing of the colors displayed to the user bypasses the problemof having colors displayed by a liquid crystal strip when those colorsare associated with a temperature outside of the desired temperaturerange. By way of example only, without the inventions disclosed herein auser would generally be unable to display a Color Display Range that istwo degrees Celsius wide because as one of ordinary skill in the knows,the tightest temperature resolution that a green color or a red colorcan be displayed is 0.5° C., which results in a Color Display Range offour degrees Celsius ((one degree Celsius for the red Color Range)+(onedegree Celsius for the green Color Range)+(one and one-half degreeCelsius for the blue Color Range)+(one and one-half degree Celsius forthe purple Color Range)). With the inventions discussed herein, however,the Color Display Range can be narrowed to one degree Celsius or twodegree Celsius by applying a mask to the liquid crystal layer thatfilters out the blue Color Range and the purple Color Range, whileallowing the red Color Range and the green Color Range to pass through.Moreover, such narrowing can eliminate the need for the use of the priorart thermochromic liquid crystal strips, such as discussed herein inregard to FIG. 1D through FIG. 1G containing multiple panels andmultiple formulations, because the user can rely on a thermochromicliquid crystal strip or thermochromic liquid crystal structure orthermochromic liquid crystal device containing just a single displaypanel. Doing so can eliminate the need for more than one thermochromicliquid crystal formulation, and thus eliminate the cost associated withthe manufacture of more than one thermochromic liquid crystalformulation. Further, doing so can also eliminate the confusion thatarises from the use of two or more thermochromic liquid crystalformulations (and the multiple permutations generated by their use, asexplained herein in relation to FIG. 1D through FIG. 1G).

These advantages are generated, as illustrated in FIG. 6A through FIG.6D in conjunction with FIG. 5, due to the operation of physics andoptics by and on the component parts of the novel Indicator structure555. Specifically, as described herein, thermochromic liquid crystalscan reflect different colors depending on the temperature thethermochromic liquid crystals are exposed to. Liquid crystalformulations are characterized by its associated Red Start temperatureand its Color Play. Below the Red Start temperature, a liquid crystalfilm may appear black because the top layer of the bottom layer cantypically be painted black. However, as the film is heated throughoutthe Color Display Range of a given novel Indicator, the novel Indicatorcan first appear red, then appear green, then appear blue, then appearpurple and finally become black again as the temperature is increasedover a given temperature range. For simplicity, and as described herein,the temperature ranges over which the colors can be seen is typicallywell-defined.

For example, a liquid crystal formulated to have a Red Start temperatureof about 2.0° C. will appear black at temperatures below 2.0° C.Further, if this formulation has a Color Play (which is the equivalentof the Color Range of red, plus the Color Range of green) of about twodegrees Celsius, the color red will be visible from about 2.0° C. untilit reaches about 3.0° C., when the color green (with a Color Range ofone about degree Celsius) will be visible. The green Color Range willlast from about 3.0° C. until it reaches about 4.0° C. when it starts toturn blue. It should be noted that the transition from green to blue isnot a sharp one, as the color blue contains many hues of green (i.e.,the color blue contains many different wavelengths associated with thecolor green). The color blue, with its Color Range of about three andone-half times that of red or green, will then be visible from about4.0° C. to about 7.5° C., when it begins to turn purple. The colorpurple, with its Color Range of about three and one-half times that ofred or green, will then be visible from about 7.5° C. until about 11.0°C., at which point the liquid crystal films will appear black because ofthe black color of the backing layer of the strip. The extended ColorRanges of the color blue and the color purple in comparison to the ColorRange of the color red and the color green collectively, is a featurecommon to thermotropic and thermochromic liquid crystal formulations.The combination of all these Color Ranges results in a Color DisplayRange equal to nine degrees Celsius.

A way to collapse that nine degrees Celsius Color Display Range to anarrower one is what is desirable. There are at least two ways toaccomplish this. The first, as shown in FIG. 6A, employs a template 625or 635 of a single solid color, and that alternately: i) contrasts withand blocks all color reflected by the thermochromic liquid crystal inthe novel Indicator or novel Indicator structure 555 when thethermochromic liquid crystal is at a certain temperature or certain setof temperatures; and ii) blends in with but still blocks the colorreflected by the thermochromic liquid crystal in the novel Indicator ornovel Indicator structure 555 when the thermochromic liquid crystal isat a second temperature or second set of temperatures, so as to convey amessage to the user only at predetermined temperatures.

The second, as shown in FIG. 6B, employs a mask 670 comprised preferablyof two separate portions, wherein each portion is a different color. Andeach color of the mask interacts with a color reflected by thethermochromic liquid crystal in the novel Indicator or novel Indicatorstructure 555 when the thermochromic liquid crystal is at a certaintemperature or certain set of temperatures (the “reflected color(s)”).More specifically, each portion of the mask 670 will selectively allowcertain reflected color(s) to pass through so that they can be viewed bythe user, while simultaneously selectively blocking or filtering certainother reflected color(s) from passing through so that they cannot beviewed by the user. In this embodiment not only can a message bedisplayed (due to either just the user viewing the color(s) not filteredout, or by the two colors interacting so as to form a message orindication), but the Color Display Range can be narrowed a great dealmore than by using the template 625 or 635 described herein in regard toFIG. 6A. It should be noted that the mask 670 can be achieved by onlyusing a single portion (i.e., a single color filter), but the mask 670works better when the two colors are used because of the contrastprovided the two colors interacting with each other to form theindication or message.

In regard to the embodiment illustrated in FIG. 6A, it is useful tostart the description of the embodiment without a template in place,which is shown in row 610 of FIG. 6A. All of FIG. 6A (i.e., Row 610, Row620 and Row 630) is a representation of the what a user would see whenlooking at the top layer 540 of a novel Indicator structure 555illustrated in FIG. 5, but in a top down view of that top layer 611, soas to provide an example of the novel Indicator or novel Indicatorstructure 555 as it moves through its Color Display Range, (with eachpanel in each Row (i.e., Panel 610 a, Panel 610 b, etc.) being arepresentation of a color displayed by an example liquid crystal novelIndicator structure 555 at a specific temperature.

The exemplary novel Indicator structure 555 in Row 610 has a Red Starttemperature of 2° C., and a Color Range of about one degree Celsius,thereby causing the liquid crystal novel Indicator structure 555 toreflect red through the top layer 540 of the novel Indicator structure555, (which is the top layer 611 in all of FIG. 6A) in the range between2° C. and 3° C. Similarly, the same liquid crystal novel Indicatorstructure 555 has a Green Start temperature of about 3° C., and a ColorRange of one about degree Celsius thereby causing a green color in therange of about 3° C. to about 4° C. The Blue Start of the blue color isat about 4° C. and because the blue has a Color Range of about three andone-half degrees Celsius, the novel Indicator structure 555 is blue fromabout 4° C. to about 7.5° C. will start turning from blue to purple atabout 7.5° C. It should be noted that the transition from green to blueis not a sharp one, as the color blue contains many hues of green (i.e.,the color blue contains many different wavelengths associated with thecolor green). Finally, the purple color has a Purple Start at about 7.5°C. with a Color Range of about three and one-half degrees, and so thenovel Indicator structure 555 is will be purple from about 7.5° C. untilabout 11° C., where it turns black.

More particularly, as shown in FIG. 6A Row 610, as the novel Indicatoror novel Indicator structure 555 in FIG. 6A Row 610 rises from 0° C. to1° C., the novel Indicator would have not yet reached its Red Starttemperature and would be a black color 610 a. But then at about 2° C.the novel Indicator or novel Indicator structure 555 would reflectthrough the top layer 611 the start of a red color 610 b, and as thetemperature warms to about 2.3° C. the color of the novel Indicator ornovel Indicator structure 555 is a more intense red 610 c. As the novelIndicator or novel Indicator structure 555 continues to warm to about2.8° C., the red color becomes more like a red with a hint of green 610d. Because the Color Range of the red color is only about one degreeCelsius, as the temperature continues to rise and reaches the about 3°C. Green Start, the novel Indicator structure 555 or Indicator begins toturn green 610 e. At about 3.5° C. the color of the novel Indicatorstructure 555 or Indicator can be a more intense green 610 f. Becausethe Color Range of the green color is only about one degree Celsius, atabout 4° C. the novel Indicator structure 555 or Indicator begins toturn blue 610 g. At 5° C. the novel Indicator structure 555 can reflecta greenish blue 610 h because of green hues or wavelengths still beingreflected by the liquid crystal to the user. Because the Color Range ofblue is larger than either red or green, at about 6° C. the Structure orIndicator will still be blue 610 i and has lost most or all of thegreenish hues, and at about 7.5° C. the novel Indicator structure 555 orIndicator will start to turn to purple 610 j. At about 9° C. the novelIndicator structure 555 or Indicator will start to move from purple to apurple-black 610 k, and because the Color Range of purple is about threeand one-half degrees Celsius, at about 11° C. the novel Indicatorstructure 555 or Indicator is black 610 l.

As discussed herein, when an end user used a prior art Indicator todiscern temperature, instructions or messages similar to those shown inFIG. 6C and FIG. 6D are typically provided to the user, so that the usercan know how to interpret either the temperature of the prior artIndicator, or know what to do when the prior art Indicator is at acertain temperature. For instance, language may be included near theprior art Indicator 120 or in a separate document (see for example FIG.1G or FIG. 1H), that contains user instructions declaring by way ofexample only, “if a red, green or blue color is visible, thentemperature is in the range between 2° C. and 8° C.” or more precisely“if a red color is visible then the temperature is between 2° C. and 3°C., if a green color is visible then the temperature is between 3° C.and 4° C., and if a blue temperature is visible then the temperature isbetween 4° C. and 8° C.”

Turning back to the embodiment illustrated in FIG. 6A, in order tosimplify the interpretation of thermochromic liquid crystal Indicatorsas well as to narrow the number of colors displayed in the Color DisplayRange, a template 625 may be printed on the top layer 540 of the novelIndicator structure 555, so that as the template contrasts with thecolor displayed through the top layer 611 it reveals a message orinstruction to the user when the Indicator is at a first temperature orfirst range of temperatures, and then the template 625 blends in withthe color reflected by the novel Indicator structure 555 through the toplayer 611 when the novel Indicator structure 555 is at a secondtemperature or second set of temperatures. As discussed herein, FIG. 6Aemploys a template 625 that can preferably be a single solid color,wherein that solid color: i) contrasts with and blocks all colorsreflected by the thermochromic liquid crystal in the novel Indicatorstructure 555 or Indicator through the top layer 611 when thethermochromic liquid crystal is at a first temperature or first set oftemperatures; and ii) blends in with but still blocks the colorreflected by the thermochromic liquid crystal in the novel Indicatorstructure 555 or Indicator through the top layer 611 when thethermochromic liquid crystal is at a second temperature or second set oftemperatures, wherein that blending and contrasting serve to convey amessage to the user only at predetermined temperatures.

By way of example only, Row 620 in FIG. 6A illustrates how to display amessage to the user (e.g., “LOAD”) when the user is interested inknowing when the Object is within the predetermined Packing TemperatureRange of between about 2° C. (Panel 620 b) and about 5° C. (Panel 620 g)so that he or she knows it is safe to assemble the cooler system andload the Product into the assembled cooler system. This embodiment isvery useful when the end user is not interested in the precisetemperature of the Object, but rather is interested to know if thetemperature of the Object is within a certain temperature range. Thisapproach is based on the Color Ranges described herein for Row 610, butas shown in FIG. 6A Row 620 and Row 630, a template 528 or 625 can beplaced on top of the top layer 540 of the exemplary liquid crystal novelIndicator structure 555 so as to provide contrast between the solidblack color of the template 528 or 625 and the colors reflected by theliquid crystal layer 550 through the clear portions of the template 637as well as portions of the top layer 540 not containing any template611, to the user so as to allow the “LOAD” message to be displayed tothe user at predetermined temperatures. The message can be usually verysimple and can also be intuitively interpreted by the end user, butcould be replaced by any message listed in FIG. 6C (by way of exampleonly, a message intended to covey an “action” or “positive” message).

More particularly and by way of example only, as shown in FIG. 6A in Row620, the template 625 is colored black (and when visible, displays themessage “LOAD”), and at 1° C. the color reflected by the Structure 555is black 620 a because the liquid crystal had not yet reached the RedStart temperature of 2° C. Thus, because the template 625 is coloredblack, it is not visible to the user and blends in with the blackbackground of the Structure 555.

Then, as the Indicator reaches its Red Start temperature of about 2° C.the Structure 555 starts to display red 620 b and the black template 625starts to become visible because of the contrast between it and the redcolor reflected by the liquid crystal visible through the top layer 611.This is important because the contrast between the red of the liquidcrystal layer 540 and the black ink of the template 625, indicates tothe user that the Object being monitored by the novel Indicator or novelIndicator structure 555 is within the Packing Temperature Range, and assuch the cooler system could be assembled and the Product can be safelyplaced within that assembled cooler system.

And as the temperature advances to about 2.3° C., the red 620 c becomesmore pronounced as does the black template 625, and that red colorstarts to turn slightly green 620 d at about 2.8° C. As the temperaturecontinues to rise, the red color turns much more green, and at about3.0° C. the novel Indicator structure 555 turns green 620 e, and theblack template 625 becomes even more pronounced. At about 3.5° C. thegreen 620 f becomes a true green, as the black template 625 becomes morepronounced. And as the temperature increases the color change continuesuntil the blue start at about 4° C. wherein the Structure begins to turnblue 620 g. Then as the novel Indicator structure 555 warms to about 5°C. the blue color becomes more evident (620 h), and the black color ofthe template 625 begins to fade as it begins to blend in with the bluecolor.

The fact that the novel Indicator structure 555 is reaching 5° C. isimportant, because when the Structure reaches 5° C. it also means thatthe Object that the Indicator or Structure 55 is monitoring is startingto reach 5° C., and as such the Object is about to start moving outsideof its Packing Temperature Range. Therefore, it is desired and importantthat the “LOAD” instruction contained on the template 625 begin to fade,so that the user is no longer instructed to pack the Product into thecooler system for all the reasons described herein. Using a black colorfor the template 625 is advantageous because as the Structure begins towarm further, for example to 6° C. 620 i and then to 9° C. 620 k, thetemplate will better match the color reflected by the liquid crystal inthe novel Indicator structure 555. This matching of the template 625 tothe Structure when the Structure is outside of the Packing TemperatureRange has the added advantage of reducing the Color Display Range of theStructure shown in FIG. 6A Row 620 from nine degrees Celsius (i.e.,color reflected by the liquid crystal is visible from about 2° C. toabout but not including 11° C. without the template 625), toapproximately six degrees Celsius (i.e., color reflected by the liquidcrystal is visible from about 2° C. to about but not including 8° C.with the template 625).

Similarly, a blue template (not shown) could be substituted for theblack template 625 in Row 620, and in doing so good contrast is observedbetween the blue color of the template and the red and green colorsdisplayed by the novel Indicator structure 555 at 2.3° C. and 3.5° C.,respectively. The blue color of the template blends especially well withthe blue and purple colors displayed by the Structure at 7.5° C. and 9°C., respectively; and thereby narrows the Color Display Range of theStructure by aiding in concealing the extended blue Color Range and theextended purple Color Range. However, when the temperature of the novelIndicator structure 555 is below the red start temperature (e.g., 1° C.)or above the end of the purple Color Range (e.g., 11° C.), the bluecolor of the template may not provide the 1 sufficient blending of theblue template with the black color of the novel Indicator structure 555at those temperatures, and thus can be somewhat visible.

In reference to FIG. 6A, another approach to using a template 625 toprovide a message or indication that the Object is or is not at adesired temperature is to use a “take no action” or “negative” mask thatconveys a message at temperature ranges different than those used indiscussing the embodiments in Row 620 of FIG. 6A. In this embodiment, itassumed that the desired Packing Temperature Range is only one or twodegrees Celsius and ranges from about 3.2° C. to about 3.8° C., and soas illustrated in Row 630 of FIG. 6A, the template purposely contrastswith the colors outside that desired Packing Temperature Range so as towarn the user when the Object is not within the desired PackingTemperature Range, while also blending in with the colors of theStructure and becoming less visible when the Structure (and the Objectto which it is monitoring) are within the desired Packing TemperatureRange. In this case, no message is revealed by the novel Indicatorstructure 555 when the novel Indicator structure 555 is within a portionof the temperature range of the Color Range for green, and a message isevident at all other temperature conditions. This approach is shown inFIG. 6A row 630 and is also very useful when the end user is notinterested in operating within a very precise temperature range, butrather is interested to know if the temperature is within a certainbroader temperature range. FIG. 6A row 630 is a representation in of thecolors that an example liquid crystal novel Indicator structure 555displays over a range of temperatures with a green mask 635 (also ingrayscale) overlaid with a “NO” message. The message is usually verysimple and is intuitively interpreted by the end user. Each panel in Row630 is a combination of the template 635 laid over the top layer 611 ofthe novel Indicator structure 555, and is viewed by the used in a topdown view is a representation of a color displayed by an example liquidcrystal film at a specific temperature, wherein the interaction of thetop layer 611 and the green template 635 contrast with each other atcertain temperatures so as to display a “NO” message to the user.

For Row 630 illustrated in FIG. 6A, the formulation of the liquidcrystal is slightly different, in that it has a Red Start temperature ofabout −1° C., and a red Color Range of about three degrees Celsius,thereby causing the liquid crystal novel Indicator structure 555 toreflect red through the top layer 540 of the novel Indicator structure555, (which is the top layer 611 in all of FIG. 6A) in the range betweenabout −1° C. and about 1° C. Similarly, the same liquid crystal novelIndicator structure 555 has a Green Start of about 2° C., and a ColorRange of about three degrees Celsius thereby causing a green color inthe range of about 2° C. to about 5° C.

It is contemplated that in the event the formulation for the red ColorRange or the green Color Range does not last the entire desired width(e.g., in this example it is three degrees Celsius), a formulation thatis the combination of more than one formulation is contemplated, eachwith slightly different Red Start and Green Start, so as to increase thered Color Range and the green Color Range to the desired width,

The Blue Start of the blue color is at about 5° C. and because the bluehas a Color Range of about ten and one-half degrees Celsius, the novelIndicator structure 555 is blue from about 5° C. to about 15.5° C. andwill start turning from blue to purple at about 15.5° C. It should benoted that the transition from green to blue is not a sharp one, as thecolor blue contains many hues of green (i.e., the color blue containsmany different wavelengths associated with the color green). Finally,the purple color has a Purple Start at about 15.5° C. with a Color Rangeof about ten and one-half degrees, and so the novel Indicator structure555 is will be purple from about 15.5° C. until about 26° C., where itturns black.

More particularly, as shown in FIG. 6A in Row 630, the template 635 iscolored green and because it contrasts with the black of the Indicatoror Structure at about −2° C. 630 a and at about 26° C. 630 l, themessage displayed by the template 635 (“NO”) is very visible. As theIndicator or novel Indicator structure 555 reaches its Red Starttemperature of about −1° C. the novel Indicator structure 555 starts todisplay red 630 b but the green template 635 is still very visible. Andas the temperature advances to about 0° C., the red 630 c becomes morepronounced and the green template 635 starts to blend into the red colorof the novel Indicator structure 555. As the temperature of theIndicator or Structure continues to rise, the red color starts to turnto slightly green 630 d so that at about 1° C. the green template 635 isnoticeably starting to blend with the reddish green color of theStructure.

Then at about 2.0° C. the novel Indicator structure 555 turns noticeablygreen 630 e, and the green template 635 becomes even more blended withthe top layer 611 of novel Indicator structure 555, and at this pointthe “negative” or “take no action” message of “NO” is not obviouslyvisible to the user, and is preferably not visible at all. This isimportant because the lack of contrast between the green of the liquidcrystal layer 540 and the green of the template 635, and thus thevirtual disappearance of the “NO” message, indicates to the user thatthe Object being monitored by the Indicator or novel Indicator structure555 is within the Packing Temperature Range, and as such the coolersystem could be assembled and the Product can be safely placed withinthat assembled cooler system.

Turning back to FIG. 6A, at 3.0° C. the green 620 f of the novelIndicator structure 555 is more intense and so continues to closelymatch the green template 635, so that the green template 635 continuesto be almost completely blended away (and preferably completely blendedaway) and in so blending, almost totally obscures (and preferablycompletely obscures) the “NO” message of the template 635.

This blending and obscuring of the “NO” message (and thus the indicationthat the Object had reached its desired temperature) continues throughabout the 4.0° C. mark 630 g, until the Blue Start occurs at about 5°C., wherein the novel Indicator structure 555 begins to turn blue 630 h,and the green color of the template 635 begins to become visible again.The fact that the novel Indicator structure 555 is reaching about 5° C.is important because it also means that the Object to which theStructure is attached is starting to reach 5° C., and as such the Objectis moving outside of its Packing Temperature Range. Therefore, it isdesired and important that the “NO” instruction contained on thetemplate 635 begin to become visible again, so that the user no longerbelieves that it is safe to pack the Product into the cooler system forall the reasons described herein.

Then as the Structure continues to warm further, for example to about10.5° C. 630 i and then to Purple Start of about 15.5° C. 630 j, thegreen template 635 will better contrast with the blue 630 h colorreflected by the novel Indicator structure 555. Then even as thetemperature of the novel Indicator structure 555 rises through thepurple Color Range, for example to 21° C., the contrast between thetemplate 635 and the top layer 611 of the novel Indicator structure 555continues to increase 630 k, and the contrast is evident when the purpleColor Range ends at about 26° C., and the novel Indicator structure 555turns black 610 l. This contrast of the green template 635 to the colorsreflected by the liquid crystal 540 of the Structure through the toplayer 611 when the novel Indicator structure 555 is outside of thePacking Temperature Range has the added advantage of reducing thethinking required by the user to determine whether the temperature ofthe Object being monitored by the Indicator or novel Indicator structure555 had moved outside the desired Packing Temperature Range, becausethat indication is accomplished only having to look for the point whenthe “negative” or “take no action” instruction is not visible.

The template 528 or 625 associated with Row 620 of FIG. 6A is made byprinting (via inkjet printer, silkscreen, or other printing methods) asolid black ink onto a transparent film which becomes the top layer 540.The transparent film or top layer 540 containing the template 528 or 625is laid on top of the liquid crystal 551, and so in effect the top layer540 of the novel Indicator structure 555 is the template 528 or 625. Itshould be appreciated that although the ink comprising the template 528or 625 could be placed on the side of the top layer 540 that faces (andthus interacts with) the liquid crystal 551, it is preferred that theink comprising the template 528 or 625 be placed on the side of the toplayer that is not facing the liquid crystal, so as to eliminate anydetrimental effects from the ink of the template 528 or 625 interactingwith the liquid crystal 551. Alternatively, the template 528 or 625could be a separate layer of transparent film that is attached to thetop layer 540 of the novel Indicator structure 555. By way of exampleonly, patterns that comprise the template 528 or 625 may be printed on acommercially available cellulose acetate film with an inkjet printer.Typically, the template 528 or 625 is made by printing dark portions 625(e.g., the letters of the message “LOAD”) around completely clearportions 627 (the non-inked portions of the message “LOAD”). The clearportions or unmasked portions 627 of the transparent film or top layer540 of the template 528 or 625 allow the colors of the underlying liquidcrystal 550 interact with both the non-inked portions and the inkedportions of the letters or symbols of the message (see FIG. 6C) so as tomake up or convey the message formed by the visible letters or symbols(see FIG. 6C). Due to the contrast between the colors reflected by theliquid crystal 551 and the colors of the template 528 or 625 the lettersor symbols comprising the message are revealed when the liquid crystal550 changes to a color different than that of the black or blue color ofthe template 528 or 625. While row 620 in FIG. 6A shows the template 528or 625 printed in black, that template 528 or 625 can be printed in adark gray or blue or purple to provide contrast with the lighter red,green, and blue colored hues of the Liquid Crystal 550, while alsoblending in with the black, blue and purple colors of the Indicator orStructure (see 620 a or 620 j or 620 k or 620 l). Basically, in the casewhen a black template 528 or 625 is used, good contrast is observedbetween the template 528 or 625 and the colors displayed by the liquidcrystal 550. However, one of ordinary skill will recognize that adifferent color could be used for the template 528 or 625, so long asthe same results are achieved as discussed herein in regard to Row 620.

The template 528 or 635 associated with Row 630 of FIG. 6A is made byprinting (via inkjet printer, silkscreen, or other printing methods) asolid green ink onto a transparent film, which becomes the top layer540. The transparent film or top layer 540 containing the template 528or 635 is laid on top of the liquid crystal 551 and so in effect the toplayer 540 of the novel Indicator structure 555 is the template 528 or635. It should be appreciated that although the ink comprising thetemplate 528 625 could be placed on the side of the top layer 540 thatfaces (and thus interacts with) the liquid crystal 551, it is preferredthat the ink comprising the template 528 or 625 be placed on the side ofthe top layer that is not facing the liquid crystal, so as to eliminateany detrimental effects from the ink of the template 528 or 625interacting with the liquid crystal 551. Alternatively, the template 528or 635 could be a separate layer of transparent film that is attached tothe top layer 540 of the novel Indicator structure 555. By way ofexample only, patterns that comprise the template 528 or 635 may beprinted on a commercially available cellulose acetate film with aninkjet printer. Typically, as shown in the example illustrated in FIG.6A row 630, the template 528 or 635 is made by printing green portions635 (e.g., the letters of the message “NO”) around completely clearportions 637 (e.g., the non-inked portions of the message “NO”). Thegreen portions of the transparent film or top layer 540 of the template528 or 635 comprise the letters or symbols of the message (see FIG. 6D).The clear portions 637, or uninked portions 637, of the transparent filmor top layer 540 of the template 528 or 635 allow the colors of theunderlying liquid crystal 550 to interact with both the non-inkedportions and the inked portions of the letters or symbols of the message(see FIG. 6D) so as to make up or convey the message formed by thevisible letters of symbols (see FIG. 6D). Due to the contrast betweenthe colors of the liquid crystal 551 and the green colors of thetemplate 528 or 635, the letters or symbols printed in the template 528or 635 and comprising the message (See FIG. 6D) are revealed as theliquid crystal 550 changes color different than that of the green colorof the template 528 or 635 due to changing temperatures. While row 630in FIG. 6A shows the template 528 or 635 printed in green, that template528 or 635 can be printed in a red, a reddish green, or any other colorthat provides contrast with the darker black, blue and purple coloredhues of the liquid crystal 550 (see 630 a or 630 c or 630 j or 630 l),while also blending in with the red and green colors of the Indicator orStructure (see 630 e or 630 g). Basically, in the case when a greentemplate 528 or 635 is used, good contrast is observed between thetemplate 528 or 635 and the colors displayed by the liquid crystal 550.However, one of ordinary skill will recognize that a different colorcould be used for the template 528 or 635, so long as the same resultsare achieved as discussed herein in regard to Row 630.

As described herein in regard to the Indicator or novel Indicatorstructure 555 depicted in FIG. 6A at 620, when a template 625 is createdwith a dark portion 625 surrounding completely clear portion(s) 627,good contrast is observed between the template 625 and the colorsdisplayed by the liquid crystal 550. Due to the strong contrast,messages are revealed clearly. And as also described herein, theopposite but similar result can be achieved when the Indicator orStructure in FIG. 6A at 630 uses a reverse non-dark template 635 (e.g.,a green color for the dark portion 635 and a clear portion 637). Whilecontrast between the template 625 or 635 and the colors of the liquidcrystal 550 contained in the novel Indicator or novel Indicatorstructure 555 is useful for many Indicator applications, thattemplate-based solution illustrated in FIG. 6A poses problems when it isdesired to reduce a color indication for a given Color Display Range toa truly narrow range of temperature (by way of example only, between twodegrees Celsius and three degrees Celsius) or when only the eliminationof a certain color is desired (e.g., eliminating red or blue). Asdescribed herein, the desired Packing Temperature Range described inregard to the novel Indicator or novel Indicator structure 555 discussedin FIG. 6A Row 620 for certain embodiments is very narrow in that it isjust three degrees Celsius (e.g., 2° C. to 5° C.), and yet it stillrequires a temperature width of nine degrees Celsius to effectuate(e.g., a Red Start at 2° C. and purple end at 11° C.). The reason forthis wide range of indication temperature is that, as discussed herein,the color blue and the color purple can persist for several degrees morethan either the red or green colors.

To overcome the prior art disadvantages of wider than desired ColorDisplay Range, and to overcome the limitations of the templates 625 and635 taught herein in conjunction with FIG. 6A, the inventors havediscovered, for example, that by using special color combinations in amask and said colors being more transparent than the colors of thetemplate embodiment, and due to said transparency when the mask isapplied the mask is able to filter certain colors reflected by thethermochromic liquid crystal but not block all colors completely as atemplate would, the Color Display Range of a given Indicator orStructure can be narrowed significantly, even if the Color Display Rangeof that the liquid crystal is customarily wide. While a simple templatecomprising clear portions and solid colored portions (by way of exampleonly, the template 625 in FIG. 6A comprised of dark ink portions 625 andclear portions 627 containing no ink) provides good contrast between thecolors of the liquid crystal 551 and the template 625 throughout themost of the Color Display Range, the inventors have invented an improvedtemplate, referred to herein as a mask 675 (and illustrated in FIG. 6B),that provides good contrast so as to enable a message to be displayed tothe user, but over a much narrower Color Display Range. Anotherdistinguishing feature is that the colors when printed in the mask 675transmit more light and are therefore more transparent compared to theopaque colors used in the template. This is achieved by applying atransparency factor to the opaque colors of the template of at leastabout 10% to 50% and preferably about 40%.

To achieve this inventive embodiment, as shown in FIG. 6B the mask 675can have a first portion 676 that is created using a predetermined firstcolor that is applied to a region of the top layer 540 of the novelIndicator structure 555, and is comprised of a second portion 677 thatis created using a predetermined second color that is applied to adifferent region of the top layer 540 of the novel Indicator structure555. The first portion 676 and the second portion 677 of the mask 675are preferably colored in colors that are more transparent than thecolors of the template embodiment, and due to said transparency when themask is applied the mask is able to filter certain colors reflected bythe thermochromic liquid crystal but not block all colors completely asa template would, so that when the first portion 676 and the secondportion 677 of the mask 675 are applied to the their respective regionsof the top layer 540 of the novel Indicator structure 555 they renderthe top layer 540 semi-transparent in regard to how the colors reflectedby the liquid crystal 551 below that top layer 540 are viewed by theuser. Thus, even though color in the form of the first portion 676 andthe second portion 677 have been added to the top layer 540 positionedabove liquid crystal layer 550, that previously clear portion of the toplayer 540 remains semi-transparent and thereby allows certain of thecolors reflected by the liquid crystal 551 to still be viewed by theuser.

The colors of the first portion 676 and the second portion 677 of themask 675 are at least 10% and up to 50% and preferably about 40% moretransparent than the opaque colors used in the template. By way ofexample, a dark green that may be used in the template can be specifiedin graphics software, such as Adobe Illustrator, Microsoft Powerpoint orother graphics software packages by the command color coordinates ofRed, Green and Blue (RGB) values of 65, 165, and 0 and a transparencyvalue of 0%, respectively on a scale from 0 to 255 for the RGB and 0 to100% on the transparency scale. This color, when sent to a digitalprinter such as an inkjet printer, laser printer or UV-curable inkprinter and printed will be dark and opaque so as to block completelyall colors reflected by the thermochromic liquid crystal and cannot beused in the mask 675 of certain embodiments of the invention. As oneskilled in the art will recognize, a more transparent color when appliedto a transparency will transmit more light compared to a darker color.

The inventors prepared a plurality of opaque colors varying in theircommand RGB coordinates and systematically evaluated the effect of thecommand transparency values on the colors reflected by the thermochromicliquid crystal composition. In this process, it was discovered that thetransparency command sent to the printer in combination with the commandRGB values plays a large role in the color filtering ability of a givenprinted mask. One of ordinary skill in the art understands that thetransparency command on most digital software is a scale from 0 to 100percent, wherein 0 percent represents the most intense color and 100percent represents the absence of the color entirely. By using thisprocess, the inventors discovered that the transparency value for a maskshould, for certain embodiments, be set between 10% and up to 60% andmost preferably between about 40% and 60%.

One skilled in the art will recognize that there are alternate mannersto denote an increasingly transparent color. For instance, on the RGBscale, a more transparent color corresponds to higher values of the RGBcoordinates. By way of example only, an RGB color with coordinates 65,165 and 0 with a transparency of 40% can also be denoted by the new RGBcoordinates of 160, 200, and 100 with a 0% transparency. Again, as oneskilled in the art will recognize, these are two different ways todenote the same color.

In particular, by coloring the first portion 676 of the mask 675 adarker shade, and coloring the second portion 677 of the mask 675 alighter shade, positioned on the top layer 540 of the novel Indicatorstructure 555, the contrast created by the first portion 676 and thesecond portion 677 when the liquid crystal 551 is reflecting a color inthe red Color Range or in the green Color Range generates a message tothe user that the Object is within its Packing Temperature Range (by wayof example only, a first color background with a lighter coloredcheckmark or “√”). Moreover, by selecting a specific color for the firstportion 676 of the mask 675 and selecting a specific color for thesecond portion 677 of the mask 675, these selected colors caneffectively filter out most of both the blue Color Range and the purpleColor Range; and as such the Color Display Range of the liquid crystal551 can be greatly reduced.

In doing so, the template 625 or 635 of FIG. 6A (which may for examplebe a solid single colored structure that is comprised of a colored darkor inked portion 625 or 635 and a clear or ink-free portion 627 or 637),is replaced by the two-portion mask 675, which is comprised of a firstcolor 676 replacing the darker colored or inked portion 625 or 635 ofthe template 625 or 635, and a second color 677 replacing the clearportion 627 or 637 of the template 625 or 635.

The key principle behind this other inventive embodiment is thesubtractive color matching that occurs when a colored semi-transparentfilm is placed in front of a light source. In this case, the lightsource is the light that reflects off of the liquid crystal 550 in theStructure 555 or Indicator when it is within the Color Display Range andis reflecting a color to the user. Typically, ambient white light willpass through the semi-transparent two portion mask 675 to the liquidcrystal layer 550, it then reflects off of the liquid crystal layer 550,and passes back through the semi-transparent two portion mask 675 to theobserver (the end user). As the white light reflects off the liquidcrystal layer 550, some of the wavelengths of light are absorbed andothers are reflected back to the user. The wavelengths that arereflected back make up the red, green, blue and purple colors displayedby a typical liquid crystal layer 550. Importantly, when a coloredfilter is applied to the light reflecting off the liquid crystal layer550, certain selected wavelengths of that reflected light can befiltered out or blocked, which effectively blocks a corresponding colorfrom being viewed by the user of the novel Indicator structure 555 orIndicator. But for those wavelengths not blocked by the colored filter,the colors corresponding to those unblocked wavelengths will be viewedby the user of the novel Indicator structure 555 or Indicator.

By way of example only, a red filter may be used to absorb or blockgreen reflected light, while simultaneously allowing red light and bluelight wavelengths to be transmitted through and viewed by the user. Inanother example, a yellow filter may be used to absorb wavelengths oflight corresponding to blue light and thereby block the color blue frombeing viewed by the user, while simultaneously allowing wavelengths oflight corresponding to red light and green light to pass through and beviewed by the user. This light absorption behavior can be preciselydetermined by obtaining a light absorption spectrum for the filter.Similarly, the light absorption behavior can be empirically determinedby creating filters of various shades and observing their effect on thelight reflected out of the liquid crystal layer 550.

For the purposes of altering or blocking certain wavelengths of lightreflected out of the liquid crystal layer 550 and so as to be blockedfrom the view of the user, by manufacturing a mask 675 that has a yellowfilter in the second portion 677 and that second portion 677 covers atleast a region of the liquid crystal layer 550, when the blue light isreflected off of the liquid crystal layer 550 at a given temperature theyellow filter in the second portion 677 of the mask 675 will block mostof that blue color from the view of the user. In this way, the liquidcrystal layer's 550 Color Display Range will be narrowed because theblue Color Range will have been mostly blocked from the view of the userby the yellow filter in the second portion 677 of the mask 675.Moreover, the yellow filter in the second portion 677 of the mask 675will also aid in mostly blocking the wavelengths associated with thecolor purple. Thus, the yellow filter in the second portion 677 of themask 675 will have aided in narrowing the Color Display Range bypartially, if not fully blocking at least the reflected blue Color Rangeand the purple Color Range.

Perhaps just as important, the yellow filter in the second portion 677of the mask 675 in certain embodiments will not fully block and insteadallows most of the red color in the red Color Range to partially passthrough the top layer 540 and be viewed by the user, although the redcolor will appear more like a light red or even a yellowish red.Similarly, the yellow filter in the second portion 677 of the mask 675will not block and instead allows the green color to pass through andappear light green to yellowish green to the user. Thus, this allows fora narrowing of the Color Display Range while still allowing the colorsimportant to the user (e.g., red and green) to be seen.

The first portion 676 of the mask 675 can also be colored so as to aidin the narrowing of the Color Display Range by at least partiallyblocking certain colors from being observed by the user. By way ofexample only by manufacturing a mask 675 that has a green filter in thefirst portion 676, and that first portion 676 covers at least a regionof the liquid crystal layer 550, so that when the blue light isreflected off of the liquid crystal layer 550 at a given temperature,the green filter in the first portion 676 of the mask 675 will filterout most and preferably all of the blue wavelengths. In this way, theliquid crystal layer's 550 Color Display Range will be narrowed becausethe blue Color Range will have been at least partially filtered out bythe green colored filter positioned in the first portion 676 of the mask675 and will at least partially block the blue Color Range from the viewof the user. Moreover, the green filter in the first portion 676 of themask 675 will also aid in at least partially blocking the wavelengthsassociated with the color purple. Thus, the green filter in the firstportion 676 of the mask 675 will have aided in narrowing the ColorDisplay Range by partially, and preferably fully blocking at least thereflected blue Color Range and the purple Color Range.

Perhaps just as important, the green filter in the first portion 676 ofthe mask 675 in certain embodiments will not fully block and insteadallows most of the red color in the red Color Range to pass through thetop layer 540 and be viewed by the user, although the red color willappear more like a dark greenish red color than a true red color.Similarly, the green filter in the first portion 676 of the mask 675will not fully block and instead will mostly allow the green color topass through and appear green to the user, and more specifically willappear a slightly darker when compared to the green passed through bythe yellow colored second portion 677 of the mask 675. Thus, this greenfilter in the first portion 676 of the mask 675 allows for a narrowingof the Color Display Range by mostly blocking the blue Color Range andpurple Color Range while still allowing the colors important to the user(e.g., red and green) to be seen.

In reference to FIG. 6B, and more particularly to Row 670, in order tonarrow the Color Display Range of a given liquid crystal in a novelIndicator structure 555 or Indicator, a mask 675 comprised of a firstportion 676 and a second portion 677 may be applied to at least aportion of the top layer 540 of the novel Indicator structure 555 so asto reveal a message to the user only when the temperature of the liquidcrystal 550 is in the red Color Range and/or in the green Color RangePlay (thereby narrowing the Color Display Range to just the desiredPacking Temperature Range).

FIG. 6B illustrates how the first portion 676 and the second portion 677of the mask 675 narrow the Color Display Range of the Indicator or novelIndicator structure 555 by reducing if not eliminating the blue ColorRange and the purple Color Range from view by the user. By way ofexample only, FIG. 6B shows the mask 675 colored yellow in the secondportion 677 and green in the first portion 676. When that mask 675 isapplied to the novel Indicator structure 555 and the novel Indicatorstructure 555 is at about 1° C. or less, the message (in the form of thesecond portion 677 shaped like a “check mark” or “√” combined with thefirst portion 676 that forms the “check mark” or “√”) can not be viewedby the user because the liquid crystal layer 550 is not reflecting anycolor 670 a and thus the novel Indicator structure 555 appears black.

Once the Red Start is reached at about 2° C. the color red 670 b becomesvisible in the first portion 676 of the mask 675 because the greenfilter that is the first portion 676 allows the red wavelengths to passthrough to be viewed by the user (although the red Color Range is moreof a greenish red color). Simultaneously, the second portion 677 of themask, which is colored yellow, appears a lighter yellowish red colorbecause the yellow filter is allowing the red wavelengths to passthrough. This is important because the contrast between the darkergreenish red color of the first portion 676 and the lighter yellowishred of the “√” that is the second portion 677 of the mask 675, indicatesto the user that the Object being monitored by the novel Indicator ornovel Indicator structure 555 is within the Packing Temperature Range,and as such the cooler system could be assembled and the Product can besafely placed within that assembled cooler system.

The liquid crystal layer 550 continues through the red Color Range,wherein the temperature of about 2.3° C. results in a redder color inthe first portion 676 of the mask 675 and still a lighter yellowish redcolor in the second portion 677 of the mask 675, 670 c, wherein thiscontrast in colors allows the user to continue to view the message (inthis example the “√”) so that the user knows that the Object is at thedesired temperature (e.g., continues to be within the PackingTemperature Range). The same is true as the temperature of the liquidcrystal 540 moves to about 2.8° C., because the first portion 676 of themask 675 starts turning a greenish red while the second portion 677 ofthe mask 675 670 d remains a lighter yellowish red color, therebycontinuing to provide the contrast so that the user can continue to beview the message (e.g., in the form of a “√”).

As the liquid crystal layer 550 continues to warm to about 3° C. theGreen Start is reached 670 e, and the first portion 676 of the maskturns a dark green while the second portion 677 of the mask 675 turns alighter green. However, the contrast of these two green colors stillprovides a noticeable distinction so as to continue to allow the message(in the form of the “√”) to be visible to the user. This contrastbetween the darker green of the first portion 676 of the mask 675 andthe lighter green of the second portion 677 of the mask 675 continueseven as the temperature of the liquid crystal layer 540 reaches about3.5° C. 670 f. This contrast visible at 3.5° C. still indicates to theuser (in a message in the form of the “√”) that the Object is stillwithin the Packing Temperature Range, and therefore it is still safe toassemble the cooler system and pack the temperature sensitive productinto that cooler system.

Then as the temperature of the liquid crystal layer 540 reaches about4.0° C. 670 g the Blue Start temperature is reached, and the secondportion 677 of the mask 675 starts to turn a light blue because thefiltering effect achieved by the yellow color filter of that secondportion 677 partially blocks the blue wavelengths being reflected fromthe liquid crystal layer 540 from being viewed by the user, although thesecond portion 677 of the mask 675 does allow the green wavelengthspresent in the blue color to pass through, as well as allows the earlyblue wavelengths to pass through, thereby generating the lightness ofvisible in the second portion 677 of the mask 675. Similarly, the greencoloring of the first portion 676 begins to filter and block the bluewavelengths being reflected from the liquid crystal layer 540 from beingviewed by the user, although the first portion 676 of the mask 675 doesallow the green wavelengths present in the blue color to pass through,as well as allows the early blue wavelengths to pass through, therebygenerating the darker green blue visible at about 4° C. in the firstportion 676 of the mask 675.

Then as the temperature of the liquid crystal layer 540 reaches about5.0° C. 670 h the green wavelengths are mostly absent from the bluecolor, and so the second portion 677 of the mask 675 starts to turn adarker blue because the filtering effect achieved by the yellow colorfilter of that second portion 677 is blocking most of the bluewavelengths being reflected from the liquid crystal layer 540 from beingviewed by the user. Similarly, the green coloring of the first portion676 continues to filter and block even a greater amount of the bluewavelengths being reflected from the liquid crystal layer 540 from beingviewed by the user. Thus, at about 5° C. the entire top layer 540 of thenovel Indicator structure 555 appears very dark blue to almost black,because the message (which in this example is in the form of a checkmarkor “√”) is mostly if not totally obscured and is not visible to theuser.

The fact that the novel Indicator structure 555 is reaching 5° C. andthat the message (which in this example is in the form of a checkmark or“√”) is no longer visible by the user is important, because when thenovel Indicator structure 555 reaches about 5° C. it also means that theObject to which the Structure is attached is starting to reach about 5°C., and as such the Object is moving outside of its Packing TemperatureRange. Therefore, it is desired and important that the message conveyedby the mask 675 (in this exemplary example, the “√”) begin to fade atthis point, so that the user is no longer informed that the Object iswithin the Packing Temperature Range, and therefore the Product should,for certain embodiments, not be packed into the cooler system for allthe reasons described herein.

And as the liquid crystal layer 540 continues to warm to about 6° C. 670i the liquid crystal turns a deeper blue; which results in more of theblue wavelengths being blocked by both the yellow filter in the secondportion 677 and the green filter in the first portion 676 of the mask675. This trend continues through the Purple Start at 7.5° C. 675 jthrough the end of the purple Color Range at about 9.0° C. 670 k, inthat the purple color, like the blue color, is blocked by the yellowcolored filter that is the second portion 677 of the mask 675, and isblocked by the green colored filter that is the first portion 676 of themask 675. And as such the message conveyed by the mask 675 (in thisexemplary example, the “√”) is still not visible to the user of theIndicator or novel Indicator structure 555, and as such the user is notmisled into believing that the Object is within the Packing TemperatureRange. Finally, the liquid crystal layer 540 reaches 11° C. 6701 andmoves out of the Color Display Range for the novel Indicator structure555 (which is by way of example only, 2.0° C. to 11.0 C.), and no coloris reflected by the liquid crystal layer 540. Given there is noreflected light from the liquid ctrystal 551, there no message conveyedby the mask 675 (in this exemplary example, the “√”) to the user of thenovel Indicator or novel Indicator structure 555, and as such the userknows the Object is not within the Packing Temperature Range.

This blocking of the blue Color Range and the blocking of the purpleColor Range by the mask 675 has the consequential advantage of narrowingthe Color Display Range for the novel Indicator or novel Indicatorstructure 555 to approximately three degrees Celsius from what wouldhave otherwise been a nine degrees Celsius Color Display Range. Thisgreatly reduced Color Display Range allows for non-confusing indicationsand messages to be displayed to the user, while simultaneously reducingthe number of formulations needed to indicate when the Object was withinit Packing Temperature Range to, for example, just a single formulation.The mask 675 can be made by printing (via inkjet printer, silkscreen, orother printing methods) two colors onto separate regions of the toplayer 540. The second portion 677 of the mask 675 is a first color, andcan be lighter in comparison to the first portion 676 of the mask 675,which can be a much darker color by comparison. The lighter color of thesecond portion 677 can be structured so as to be in the form of asymbol(s), letter(s) or glyphs that convey the desired message to theuser. The darker color of the first portion 676 makes up the backgroundof the mask 675 and contrasts with the color of the second portion 677so as to aid in forming the message. The mask 675 may be printed on acommercially available cellulose acetate film with an inkjet printer,and preferably will use a 5 mil polyester Mylar film. One goodcombination of light and dark colors that successfully blocks the blueand purple colors from being displayed is a yellow checkmark in thesecond portion 677 (i.e., the light region) on a green background in thefirst portion 676 (i.e., the dark region), although one of ordinaryskill in the art will realize that other combinations can be used to atleast partially and preferably completely block certain other colorsreflected by the liquid crystal layer 540.

It should be noted that the colors described herein may vary dependingupon a specific computer and printer combination, as it can be verydifficult to precisely match on-screen colors to printed colors ingeneral. On the RGB color scale and in regard to the mask 675, thesecond portion 677, which can be in the form of a checkmark, is coloredyellow with very high and roughly equal red and green values and anintermediate value of blue. For example, a preferred yellow is R=255,G=255, and B=150. The colors of the second portion 677 of the mask 675should be at least 10% and up to 50% and preferably about 40% moretransparent than the opaque colors used in the template. By way ofexample, a vivid yellow that may be used in the template can bespecified in graphics software such as Adobe Illustrator, MicrosoftPowerpoint or other graphics software packages by the command colorcoordinates of Red, Green and Blue (RGB) values of 255, 255, and 0 and atransparency value of 0%, respectively on a scale from 0 to 255 for theRGB and 0 to 100% on the transparency scale. This color, when sent to adigital printer such as an inkjet printer, laser printer or UV-curableink printer and printed will be opaque so as to block completely allcolors reflected by the thermochromic liquid crystal and cannot be usedin the mask 675 of the invention. As one skilled in the art willrecognize, a more transparent color when applied to a transparency willtransmit more light compared to a darker color.

The inventors prepared a plurality of opaque colors varying in theircommand RGB coordinates and systematically evaluated the effect of thecommand transparency values on the colors reflected by the thermochromicliquid crystal composition. In this process, it was discovered that thetransparency command sent to the printer in combination with the commandRGB values plays a large role in the color filtering ability of a givenprinted mask. One of ordinary skill in the art understands that thetransparency command on most digital software is a scale from 0 to 100percent, wherein 0 percent represents the most intense color and 100percent represents the absence of the color entirely. By using thisprocess, the inventors discovered that the transparency value for a maskshould, for certain embodiments, be set between 10% and up to 60% andmost preferably between about 40% and 60%.

One skilled in the art will recognize that there are alternate mannersto denote a increasingly transparent color. For instance, on the RGBscale, a more transparent color corresponds to higher values of the RGBcoordinates. By way of example only, an RGB color with coordinates 255,255, and 0 with a transparency of 60% can also be denoted by the new RGBcoordinates of 255, 255, and 150 with a 0% transparency. Again, as oneskilled in the art will recognize, these are two different ways todenote the same color. The color with RGB coordinates 255, 255, and 150most closely resembles Pantone 461C. However, the RGB blue value mayrange from 70-200 and still preserve a yellow color useful for blockingout the blue Color Range and the purple Color Range.

The colors applied to the to the second portion 677 can be applied usingdigital processes such as inkjet, laser, or UV-curable ink processes orscreen printing processes. If applied using UV-curable inks, theprinting is performed on an Océ Variadot Arizona 480 GT flat bed printermanufactured by Canon. The printer prints with a resolution of 1440×1440dots per inch (DPI).

With regard to the color specifications of the dark background of thefirst portion 676 of the mask 675 of FIG. 6B, it can be a green with adominant RGB green value, an intermediate RGB red value, and anintermediate to low RGB blue value. For example, a preferable green isR=150, G=200, and B=100. The colors of the first portion 676 of the mask675 is at least 10% and up to 50% and preferably about 40% moretransparent than the opaque colors used in the template. By way ofexample, a vivid and opaque green that may be used in the template canbe specified in graphics software such as Adobe Illustrator, MicrosoftPowerpoint or other graphics software packages by the command colorcoordinates of Red, Green and Blue (RGB) values of 65, 165 and 0 and atransparency value of 0%, respectively on a scale from 0 to 255 for theRGB and 0 to 100% on the transparency scale. This color, when sent to adigital printer such as an inkjet printer, laser printer or UV-curableink printer and printed will be opaque so as to block all colorsreflected by the thermochromic liquid crystal and may not be used in themask 675 of the invention. As one skilled in the art will recognize, amore transparent color when applied to a transparency can transmit morelight compared to a darker color.

The inventors prepared a plurality of opaque colors varying in theircommand RGB coordinates and systematically evaluated the effect of thecommand transparency values on the colors reflected by the thermochromicliquid crystal composition. In this process, it was discovered that thetransparency command sent to the printer in combination with the commandRGB values plays a role in the color filtering ability of a givenprinted mask. One of ordinary skill in the art understands that thetransparency command on digital software is a scale from 0 to 100percent, wherein 0 percent represents the most intense color and 100percent represents the absence of the color entirely. By using thisprocess, the inventors discovered that the transparency value for a maskcould, for certain embodiments, be set between 10% and up to 60% andmost preferably between about 40% and 60%.

One skilled in the art will recognize that there are alternate mannersto denote a increasingly transparent color. For instance, on the RGBscale, a more transparent color corresponds to higher values of the RGBcoordinates. By way of example only, an RGB color with coordinates 65,165 and 0 with a transparency of 40% can also be denoted by the new RGBcoordinates of 160, 200 and 100 with a 0% transparency. Again, as oneskilled in the art will recognize, these are two different ways todenote the same color. The color with RGB coordinates 160, 200, and 100closely resembles Pantone 367C. The RGB values may range slightly foreach color. For example, the red value should, for certain embodiments,range from about 145-175, the green value from 190-210, and the bluevalue from 80-120.

The colors applied to the to the second portion 677 can be applied usingdigital processes such as inkjet, laser, or UV-curable ink processes orscreen printing processes. If applied using UV-curable inks, theprinting can be performed on an Océ Variadot Arizona 480 GT flat bedprinter manufactured by Canon. That printer prints with a resolution of1440×1440 dots per inch (DPI).

One of ordinary skill in the art will recognize that many othercombinations of colors can be used in conjunction with the first portion676 of the mask 675 and the second portion 677 of the mask 675 so as toblock other colors (such as the red or green colors) reflected by thethermochromic liquid crystal 551.

An alternative to the two portion mask 675 embodiment is an embodimentthat uses a single portion, as shown in FIG. 6E. To achieve thisinventive embodiment, the mask 685 depicted in FIG. 6E is comprised of asingle first portion 685 that is created using a predetermined firstcolor that is applied to most if not all of a region of the top layer540 of the novel Indicator structure 555. This single portion mask 685is preferably applied using a half-tone printing process, so that whenthe colored filter of the single portion mask 685 is applied to itsrespective region of the top layer 540 of the novel Indicator structure555 it renders the top layer 540 semi-transparent in regard to how thecolors reflected by the liquid crystal 551 below that top layer 540 areviewed by the user. Thus, even though color in the form of the singleportion mask 685 have been added to the top layer 540 positioned aboveliquid crystal layer 550, that previously clear portion of the top layer540 remains semi-transparent and thereby allows certain of the colorsreflected by the liquid crystal 551 to still be viewed by the user.

In particular, by coloring the single portion mask 685 a certain shade,by way of example only a green color, when the liquid crystal 551reflects a color in the red Color Range or in the green Color Range amessage in the form of a reddish or green color will be displayed to theuser so as to indicate to the user that the Object is within its PackingTemperature Range (by way of example only, a red color or a greencolor), because by selecting a specific color for the single portionmask 685, the green colored filter can effectively block or filter outmost of both the blue Color Range and the purple Color Range; and assuch the Color Display Range of the liquid crystal 551 can be greatlyreduced.

For the purposes of filtering or altering or blocking certainwavelengths of light reflected out of the liquid crystal layer 550 andso as to be blocked from the view of the user, by manufacturing thesingle portion mask 685 to be colored so as to aid in the narrowing ofthe Color Display Range by at least partially blocking certain colorsfrom being observed by the user. By way of example only by manufacturinga mask 685 that has a green filter in the single portion mask 685, andthat single portion mask covers at least a region of the liquid crystallayer 550, so that when the blue light is reflected off of the liquidcrystal layer 550 at a given temperature, the green filter in the singleportion mask 685 will filter out most and preferably all of the bluewavelengths. In this way, the liquid crystal layer's 550 Color DisplayRange will be narrowed because the blue Color Range will have been atleast partially filtered out by the green colored filter of the singleportion mask 685 and will at least partially block the blue Color Rangefrom the view of the user. Moreover, the green filter in the singleportion mask 685 will also aid in at least partially blocking thewavelengths associated with the color purple. Thus, the green filter inthe single portion mask 685 will have aided in narrowing the ColorDisplay Range by partially, and preferably fully blocking at least thereflected blue Color Range and the purple Color Range.

Perhaps just as important, the green filter in the single portion mask685 will not fully block and instead allows the red color in the redColor Range to pass through the top layer 540 and be viewed by the user,although the red color will appear more like a greenish red color than atrue red color. Similarly, the green filter in the single portion mask685 will not fully block and instead will allow, at least in part thegreen color to pass through and appear green to the user. Thus, thisgreen filter in the single portion mask 685 allows for a narrowing ofthe Color Display Range by blocking, at least in part the blue ColorRange and purple Color Range while still allowing the colors importantto the user (e.g., red and green) to be seen.

In reference to FIG. 6E, and more particularly to Row 690, in order tonarrow the Color Display Range of a given liquid crystal in a novelIndicator or novel Indicator structure 555, a single portion mask 685comprised of the single mask 685 may be applied to at least a portion ofthe top layer 540 of the novel Indicator structure 555 so as to reveal amessage to the user only when the temperature of the liquid crystal 550is in the red Color Range and/or in the green Color Range Play (therebynarrowing the Color Display Range to just the desired PackingTemperature Range).

FIG. 6B illustrates how the single portion mask 685 narrows the ColorDisplay Range of the novel Indicator or novel Indicator structure 555 byreducing if not eliminating the blue Color Range and the purple ColorRange from view by the user. By way of example only, FIG. 6E shows thesingle portion mask 685 colored green. When that single portion mask 685is applied to the novel Indicator structure 555 and the novel Indicatorstructure 555 is at about 1° C. or less, the message (by way of exampleonly would be in the form of a reddish or green color) can not be viewedby the user because the liquid crystal layer 550 is not reflecting anycolor 680 a and thus the novel Indicator structure 555 appears black.

Once the Red Start is reached at about 2° C. the color red 680 b becomesvisible in the single portion mask 685 because the green filter allowsthe red wavelengths to pass through to be viewed by the user (althoughthe red Color Range is more of a greenish red color). This is importantbecause the message or indication in the form of a greenish red color,indicates to the user that the Object being monitored by the novelIndicator or novel Indicator structure 555 is within the PackingTemperature Range, and as such the cooler system could be assembled andthe Product can be safely placed within that assembled cooler system.

The liquid crystal layer 550 continues through the red Color Range,wherein the temperature of about 2.3° C. results in a redder color inthe single portion mask 685 670 c that allows the user to continue toview the message (in this example the greenish red color) so that theuser knows that the Object is at the desired temperature (e.g.,continues to be within the Packing Temperature Range). The same is trueas the temperature of the liquid crystal 540 moves to about 2.8° C.,because the single portion mask 685 starts turning a more greenish red,thereby continuing to provide the message or indication so that the usercan continue to be view the message (e.g., in the form of a “√”).

As the liquid crystal layer 550 continues to warm to about 3° C. theGreen Start is reached 680 e, and the single portion mask 685 turns adark green. However, that green color still provides a noticeableindication so as to continue to allow the message (in the form of thegreen color) to be visible to the user. This green color indication ormessage displayed by the single portion mask 685 of the novel Indicatorstructure 555 or Indicator continues even as the temperature of theliquid crystal layer 540 reaches about 3.5° C. 670 f. This indicationvisible at 3.5° C. still indicates to the user (in a message in the formof the green color) that the Object is still within the PackingTemperature Range, and therefore it is still safe to assemble the coolersystem and pack the temperature sensitive product into that coolersystem.

Then as the temperature of the liquid crystal layer 540 reaches about4.0° C. 670 g the Blue Start temperature is reached, and the singleportion mask 685 starts to turn a light blue because the filteringeffect achieved by green color filter of that single portion mask 685partially blocks the blue wavelengths being reflected from the liquidcrystal layer 540 from being viewed by the user. Similarly, the greencoloring of the single portion mask 685 begins to filter and block theblue wavelengths being reflected from the liquid crystal layer 540 frombeing viewed by the user although it does allow the green wavelengthspresent in the blue color to pass through, as well as allows the earlyblue wavelengths to pass through, thereby generating the greenish bluevisible at about 4° C. in the single portion mask 685.

Then as the temperature of the liquid crystal layer 540 reaches about5.0° C. 680 h the green wavelengths are mostly absent from the bluecolor, and so the single portion mask 685 starts to turn a darker bluebecause the filtering effect achieved by the green color filter of thatsingle portion mask 685 is blocking most of the blue wavelengths beingreflected from the liquid crystal layer 540 from being viewed by theuser. Thus, at about 5° C. the entire top layer 540 of the novelIndicator structure 555 appears very dark blue to almost black, becausethe message (which in this example is in the form of a red or greencolor) is mostly if not totally obscured and is not visible to the user.

The fact that the novel Indicator structure 555 in certain embodimentsis reaching 5° C. and that the message (which in this example is in theform of a red or green color) is no longer visible by the user isimportant, because when the novel Indicator structure 555 reaches about5° C. it also means that the Object to which the Structure is attachedis starting to reach about 5° C., and as such the Object is movingoutside of its Packing Temperature Range. Therefore, it is desirablethat the message conveyed by the single portion mask 685 (in thisexemplary example, the red or green color) in certain embodiments beginto fade at this point, so that the user is no longer informed that theObject is within the Packing Temperature Range, and therefore theProduct should, in certain embodiments not be packed into the coolersystem for all the reasons described herein.

And as the liquid crystal layer 540 continues to warm to about 6° C. 680i the liquid crystal turns a deeper blue; which results in more of theblue wavelengths being blocked by the single portion mask 685. Thistrend continues through the Purple Start at 7.5° C. 685 j through theend of the purple Color Range at about 9.0° C. 680 k, in that the purplecolor, like the blue color, is blocked by the green colored filter thatis the single portion mask 685. And as such the message conveyed by thesingle portion mask 685 (in this exemplary example, the red or greencolor) is still not visible to the user of the Indicator or novelIndicator structure 555, and as such the user is not misled intobelieving that the Object is within the Packing Temperature Range.Finally, the liquid crystal layer 540 reaches 11° C. 6801 and moves outof the Color Display Range for the novel Indicator structure 555 (whichis by way of example only, 2.0° C. to 11.0 C.), and no color isreflected by the liquid crystal layer 540. Given there is no reflectedlight from the liquid crystal 551, there no message conveyed by thesingle portion mask 685 (in this exemplary example, the red or greencolor) to the user of the novel Indicator or novel Indicator structure555, and as such the user knows the Object is not within the PackingTemperature Range.

This blocking of the blue Color Range and the blocking of the purpleColor Range in certain embodiments has by the single portion mask 685the consequential advantage of narrowing the Color Display Range for thenovel Indicator structure 555 or Indicator to approximately threedegrees Celsius from what would have otherwise been a nine degreesCelsius Color Display Range. This greatly reduced Color Display Rangeallows for non-confusing indications and messages to be displayed to theuser, while simultaneously reducing the number of formulations needed toindicate when the Object was within it Packing Temperature Range to, forexample, just a single formulation.

One of ordinary skill in the art will know that although a green colorwas used as the colored filter in the single portion mask 685 embodimentdescribed herein, a colored filter of a color other than green couldalso be used.

The single portion mask 685 can be made by using a colored filter madeof acetate sheet or similar material that is colored to the requiredshade of green or whatever color is required. Alternatively, the singleportion mask 685 can be made by printing the green color onto the toplayer 540 as described herein. Similarly, the two portion mask 675 canbe made by using multiple colored filters formed on a single acetatesheet that contains the coloring to the required shades, such green andyellow, or whatever colors are required to accomplish the filtering andor blocking of the desired wavelengths. Or the two portion mask 675 canbe made by using multiple colored filters formed on separate acetatesheets that contain the coloring to the required shades, such green andyellow, or whatever colors are required to accomplish the filtering andor blocking of the desired wavelengths, and the colored portions arethen joined to form the mask 675.

As shown in FIG. 7A and FIG. 7B, by increasing the side of theindentions 710 to resemble the large indentation 790, the userexperience can be enhanced because the message 755 can be more easilyread.

As shown in FIG. 8, the optic 480 from FIG. 4A and FIG. 4B can bereplaced by a viewing angle film 840, and used for the same purpose ofincreasing the visual size of the message being displayed to the user bythe liquid crystal layer 540 when used in conjunction with the templates625 and 635 or the mask 675 described herein.

Although the inventions contained herein have been particularly shownand described with reference to preferred and alternative embodimentsthereof, it will be understood by those skilled in the art that variouschanges in form and detail may be made to those inventions withoutdeparting from the spirit and scope of the inventions.

What is claimed is:
 1. A temperature Indicator, comprising: a liquidcrystal structure which further comprises: a top layer; a backing layer;a single compartment positioned between said top layer and said backinglayer containing temperature sensitive liquid crystals that reflectlight at a certain color, wherein that reflected color is determined bythe temperature of the temperature sensitive liquid crystals; a templatepositioned on said top layer that is comprised of at least a firsttemplate portion and a second template portion, wherein said firsttemplate portion is a first color filter that is colored a first colorand said second template portion is a second color filter that iscolored a second color, wherein said first color and said second colorare chosen so that when the reflected color passes through said firstcolor filter it will emerge as a first filtered color, and when thereflected color passes through said second color filter it will emergeas a second filtered color, and the first filtered color and the secondfiltered color contrast with each other so as to generate a message thatis displayed to the user; and a cap or housing.
 2. The temperatureIndicator of claim 1, wherein said top layer that is exposed to ambientair possesses thermal insulative properties.
 3. The temperatureIndicator of claim 1, wherein said backing layer that is in thermalcontact with object being monitored possesses thermal conductiveproperties.
 4. The temperature Indicator of claim 1, wherein said singlecompartment contains a dopant to retard the transition speed of saidtemperature sensitive liquid crystals.
 5. The temperature Indicator ofclaim 1, wherein template is positioned on the upper side of said toplayer.
 6. The temperature Indicator of claim 1, wherein a selectedtemplate is comprised of a single color.
 7. The temperature Indicator ofclaim 1, wherein said single compartment contains a single liquidcrystal formulation.
 8. The temperature Indicator of claim 1, whereinsaid single compartment contains at least two liquid crystalformulations.
 9. The temperature Indicator of claim 1, furthercomprising: a magnifyingoptic.
 10. The temperature Indicator of claim 1,further comprising: a viewing angle film.
 11. The temperature Indicatorof claim 1, wherein said cap is positioned on top of and encases saidliquid crystal structure.
 12. The temperature Indicator of claim 1,wherein said liquid crystal structure is positioned inside said housing.13. The temperature Indicator of claim 12, wherein said housing isfurther comprised of a disc in contact with and at least partiallycovering a top portion of said housing.
 14. A temperature Indicator,comprising: a liquid crystal structure which further comprises: a toplayer; a backing layer; a single compartment positioned between said toplayer and said backing layer containing temperature sensitive liquidcrystals that reflect light at a certain color, wherein that reflectedcolor is determined by the temperature of the temperature sensitiveliquid crystals; a template positioned on said top layer that iscomprised of at least a first template portion and a second templateportion, wherein said first template portion is a first color filterthat is colored a first color and said second template portion is asecond color filter that is colored a second color, wherein said firstcolor and said second color are chosen so that when the reflected colorpasses through said first color filter it will emerge as a firstfiltered color, and when the reflected color passes through said secondcolor filter it will emerge as a second filtered color, and the firstfiltered color and the second filtered color contrast with each other soas to generate a message that is displayed to the user; and so that mostof the blue color range and most of the purple color range reflected offof said temperature sensitive liquid crystals are filtered out by saidfirst color filter and said second color filter, thereby reducing thecolor display range of said Indicator; and a cap or housing.